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EXHIBIT 4.1


EXECUTION
VERSION 


WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.,



as Depositor and Master Servicer



and



DEUTSCHE BANK NATIONAL TRUST COMPANY,



as Trustee



and



DEUTSCHE BANK TRUST COMPANY DELAWARE,



as Delaware Trustee







POOLING AND SERVICING AGREEMENT



$2,971,414,173.32



Washington Mutual Mortgage Securities Corp.



WaMu Mortgage Pass-Through Certificates



Series 2005-AR1



Cut-Off Date: January 1, 2005


 










TABLE OF CONTENTS



	
 

	
Page


	
 

	
 


	
ARTICLE I

	
6


	
Section 1.01.  Definitions

	
6


	
Adjusted Cap Rate

	
6


	
Aggregate Certificate Principal Balance

	
7


	
Appraised Value

	
7


	
Assignment of Proprietary Lease

	
7


	
Authenticating Agent

	
7


	
Authorized Denomination

	
7


	
Bankruptcy Loss

	
8


	
Beneficial Holder

	
8


	
Benefit Plan Opinion

	
8


	
Book-Entry Certificates

	
8


	
Business Day

	
8


	
Buydown Agreement

	
8


	
Buydown Fund

	
8


	
Buydown Fund Account

	
9


	
Buydown Loan

	
9


	
Cap Strike Rate

	
9


	
Carry-Forward Subsequent Recoveries Amount

	
9


	
Carryover Shortfall Amount

	
9


	
Carryover Shortfall Payment

	
9


	
Certificate

	
10


	
Certificate Account

	
10


	
Certificateholder or Holder

	
10


	
Certificate Interest Rate

	
10


	
Certificate of Trust

	
10


	
Certificate Principal Balance

	
10


	
Certificate Register and Certificate Registrar

	
10


	
Class

	
10


	
Class A Certificates

	
11


	
Class A-L Regular Interests

	
11


	
Class A-1A Certificates

	
11


	
Class A-1A-L Regular Interest

	
11


	
Class A-1B Certificates

	
11


	
Class A-1B-L Regular Interest

	
11


	
Class A-2A1 Certificates

	
11


	
Class A-2A1-L Regular Interest

	
12


	
Class A-2A2 Certificates

	
12


	
Class A-2A2-L Regular Interest

	
12


	
Class A-2A3 Certificates

	
12


	
Class A-2A3-L Regular Interest

	
12


	
Class A-2B Certificates

	
12


	
Class A-2B-L Regular Interest

	
12


	
Class A-3 Certificates

	
12


	
Class A-3-L Regular Interest

	
12


	
Class B Certificates

	
12


	
Class B-L Regular Interests

	
12


	
Class B-1 Certificates

	
12


	
Class B-1-L Regular Interest

	
12


	
Class B-2 Certificates

	
12


	
Class B-2-L Regular Interest

	
13


	
Class B-3 Certificates

	
13


	
Class B-3-L Regular Interest

	
13


	
Class B-4 Certificates

	
13


	
Class B-4-L Regular Interest

	
13


	
Class B-5 Certificates

	
13


	
Class B-5-L Regular Interest

	
13


	
Class B-6 Certificates

	
13


	
Class B-6-L Regular Interest

	
13


	
Class LT Principal Reduction Amounts

	
13


	
Class LT Regular Interests

	
13


	
Class LT1 Regular Interest

	
13


	
Class LT2 Principal Distribution Amount

	
13


	
Class LT2 Regular Interest

	
14


	
Class LT3 Principal Distribution Amount

	
14


	
Class LT3 Regular Interest

	
14


	
Class LT4 Principal Distribution Amount

	
14


	
Class LT4 Regular Interest

	
14


	
Class Notional Amount

	
14


	
Class Principal Balance

	
14


	
Class R Certificates

	
15


	
Class R Residual Interests

	
15


	
Class R-1 Residual Interest

	
15


	
Class R-2 Residual Interest

	
15


	
Class X Certificates

	
15


	
Class X-L Notional Amount

	
15


	
Class X-L Regular Interest

	
15


	
Class Y Certificates

	
16


	
Clean-Up Call Option Date

	
16


	
Clean-Up Call Percentage

	
16


	
Clearing Agency

	
16


	
Closing Date

	
16


	
Code

	
16


	
Company

	
16


	
Compensating Interest

	
16


	
Cooperative

	
16


	
Cooperative Apartment

	
16


	
Cooperative Lease

	
16


	
Cooperative Loans

	
16


	
Cooperative Stock

	
17


	
Cooperative Stock Certificate

	
17


	
Corporate Trust Office

	
17


	
Corporation

	
17


	
Corresponding Class

	
17


	
Credit Support Depletion Date

	
17


	
Cumulative Carry-Forward Subsequent Recoveries Amount

	
17


	
Curtailment

	
18


	
Curtailment Shortfall

	
18


	
Custodial Account for P&I

	
18


	
Custodial Account for Reserves

	
18


	
Custodial Agreement

	
19


	
Custodian

	
19


	
Cut-Off Date

	
19


	
Definitive Certificates

	
19


	
Delaware Trustee

	
19


	
Depositary Agreement

	
19


	
Destroyed Mortgage Note

	
19


	
Determination Date

	
19


	
Disqualified Organization

	
19


	
Distribution Date

	
19


	
DTC

	
19


	
DTC Participant

	
19


	
Due Date

	
19


	
Eligible Institution

	
19


	
Eligible Investments

	
20


	
ERISA

	
21


	
ERISA Restricted Certificate

	
21


	
Event of Default

	
21


	
Excess Liquidation Proceeds

	
21


	
Excess Subsequent Recoveries

	
22


	
Fannie Mae

	
22


	
FDIC

	
22


	
FHA

	
22


	
Final Maturity Date

	
22


	
Fitch:

	
22


	
Freddie Mac

	
22


	
GCD

	
22


	
Index

	
22


	
Indirect DTC Participants

	
22


	
Initial Custodial Agreement

	
22


	
Initial Custodian

	
22


	
Insurance Proceeds

	
22


	
Interest Distribution Amount

	
23


	
Interest Rate Adjustment Date

	
23


	
Investment Account

	
23


	
Investment Depository

	
23


	
Junior Subordinate Certificates

	
23


	
Last Scheduled Distribution Date

	
23


	
Lender

	
23


	
LIBOR

	
23


	
LIBOR Determination Date

	
24


	
Liquidated Mortgage Loan

	
24


	
Liquidation Principal

	
24


	
Liquidation Proceeds

	
24


	
Loan-to-Value Ratio

	
24


	
Lowest Class B Owner

	
24


	
Marker Rate

	
24


	
Master Servicer

	
24


	
Master Servicer Business Day

	
24


	
Master Servicing Fee

	
24


	
Master Servicing Fee Rate

	
25


	
MERS

	
25


	
MERS Loan

	
25


	
MERS® System

	
25


	
MIN

	
25


	
Minimum Monthly Payment

	
25


	
MOM Loan

	
25


	
Monthly P&I Advance

	
25


	
Monthly Payment

	
25


	
Monthly Payment Adjustment Terms

	
25


	
Moody’s

	
25


	
Mortgage

	
25


	
Mortgage File

	
25


	
Mortgage Interest Rate

	
28


	
Mortgage Loan Margin

	
28


	
Mortgage Loan Schedule

	
28


	
Mortgage Loans

	
29


	
Mortgage Note

	
29


	
Mortgage Pool

	
29


	
Mortgage Pool Assets

	
29


	
Mortgaged Property

	
29


	
Mortgagor

	
30


	
Negative Amortization Amount

	
30


	
Net Negative Amortization Amount

	
30


	
No-Delay Accrual Period

	
30


	
Nonrecoverable Advance

	
30


	
Non-U.S. Person

	
30


	
Notice Addresses

	
30


	
Novation Agreement

	
31


	
OTS

	
31


	
Officer’s Certificate

	
31


	
One-Year MTA

	
31


	
Opinion of Counsel

	
31


	
Original Trust Agreement

	
31


	
Original Value

	
31


	
Ownership Interest

	
31


	
Pass-Through Entity

	
32


	
Pass-Through Rate

	
32


	
Paying Agent

	
32


	
Payoff

	
32


	
Payoff Earnings

	
32


	
Payoff Interest

	
32


	
Payoff Period

	
32


	
Percentage Interest

	
33


	
Permitted Transferee

	
33


	
Person

	
34


	
Prepaid Monthly Payment

	
34


	
Primary Insurance Policy

	
34


	
Principal Balance

	
34


	
Principal Payment

	
35


	
Principal Payment Amount

	
35


	
Principal Prepayment

	
35


	
Principal Prepayment Amount

	
35


	
Prior Period

	
35


	
Pro Rata Allocation

	
35


	
Prospectus

	
35


	
Purchase Obligation

	
35


	
Purchase Price

	
35


	
Qualified Insurer

	
36


	
Rate Ceiling

	
36


	
Rating Agency

	
36


	
Ratings

	
36


	
Realized Loss

	
36


	
Recognition Agreement

	
38


	
Record Date

	
38


	
Regular Interests

	
38


	
Relief Act Shortfall

	
38


	
Reference Banks

	
38


	
REMIC

	
38


	
REMIC Provisions

	
38


	
REMIC I

	
38


	
REMIC I Assets

	
39


	
REMIC I Available Distribution Amount

	
39


	
REMIC I Distribution Amount

	
40


	
REMIC I Principal Distribution Amount

	
41


	
REMIC I Regular Interests

	
41


	
REMIC II

	
41


	
REMIC II Assets

	
41


	
REMIC II Available Distribution Amount

	
41


	
REMIC II Distribution Amount

	
41


	
REMIC II Regular Interests

	
44


	
Residual Certificates

	
44


	
Residual Distribution Amount

	
45


	
Responsible Officer

	
45


	
ROV Mortgage Loan

	
45


	
S&P

	
45


	
Secretary of State

	
45


	
Securities Act

	
45


	
Security Agreement

	
45


	
Selling and Servicing Contract

	
45


	
Senior Certificates

	
46


	
Senior Liquidation Amount

	
46


	
Senior Percentage

	
46


	
Senior Prepayment Percentage

	
46


	
Senior Principal Distribution Amount

	
48


	
Senior Subordinate Certificates

	
48


	
Servicer

	
48


	
Servicing Fee

	
48


	
Servicing Fee Rate

	
48


	
Servicing Officer

	
48


	
Special Primary Insurance Policy

	
48


	
Special Primary Insurance Premium

	
48


	
Statutory Trust Statute

	
48


	
Streamlined Mortgage Loan

	
48


	
Subordinate Certificates

	
49


	
Subordinate Liquidation Amount

	
49


	
Subordinate Percentage

	
49


	
Subordinate Prepayment Percentage

	
49


	
Subordinate Principal Distribution Amount

	
49


	
Subordinate Principal Prepayments Distribution Amount

	
49


	
Subordination Level

	
49


	
Subsequent Recoveries

	
49


	
Substitute Mortgage Loan

	
50


	
Tax Matters Person

	
50


	
Termination Date

	
50


	
Termination Payment

	
50


	
Transfer

	
50


	
Transferee

	
50


	
Transferee Affidavit and Agreement

	
50


	
Trust

	
50


	
Trustee

	
50


	
Uncollected Interest

	
51


	
Uncompensated Interest Shortfall

	
51


	
Underwriters

	
51


	
Underwriting Standards

	
51


	
Uninsured Cause

	
51


	
U.S. Person

	
51


	
VA

	
51


	
Weighted Average Pass-Through Rate

	
51


	
Withdrawal Date

	
51


	
Yield Maintenance Account

	
52


	
Yield Maintenance Agreement

	
52


	
Yield Maintenance Available Payment Amount

	
52


	
Yield Maintenance Notional Balance

	
52


	
Yield Maintenance Payment

	
52


	
ARTICLE II  Creation of the Trust; Conveyance of the Mortgage
Pool Assets and REMIC I Regular Interests; REMIC Election and Designations;
Original Issuance of Certificates

	
53


	
Section 2.01.  Creation of the Trust

	
53


	
Section 2.02.  Restrictions on Activities of the Trust

	
54


	
Section 2.03.  Separateness Requirements

	
54


	
Section 2.04.  Conveyance of Mortgage Pool Assets; Security
Interest

	
56


	
Section 2.05.  Delivery of Mortgage Files

	
57


	
Section 2.06.  REMIC Election for REMIC I

	
59


	
Section 2.07.  Acceptance by Trustee

	
60


	
Section 2.08.  Representations and Warranties of the Company
Concerning the Mortgage Loans

	
62


	
Section 2.09.  Acknowledgment of Transfer of Mortgage Pool
Assets

	
66


	
Section 2.10.  Conveyance of REMIC II Assets; Security
Interest

	
67


	
Section 2.11.  REMIC Election for REMIC II

	
68


	
Section 2.12.  Acknowledgement of Transfer of REMIC II Assets;
Authentication of Certificates

	
70


	
Section 2.13.  Legal Title

	
70


	
Section 2.14.  Compliance with ERISA Requirements

	
70


	
Section 2.15.  Additional Representation of the Company Concerning
the Mortgage Loans

	
70


	
Section 2.16.  Distributions to Certain Class A Certificates
Outside of REMIC II

	
70


	
 

	
 


	
ARTICLE III  Administration and Servicing of Mortgage
Loans

	
71


	
Section 3.01.  The Company to Act as Master Servicer

	
71


	
Section 3.02.  Custodial Accounts and Buydown Fund
Accounts

	
73


	
Section 3.03.  The Investment Account; Eligible
Investments

	
75


	
Section 3.04.  The Certificate Account

	
75


	
Section 3.05.  Permitted Withdrawals from the Certificate Account,
the Investment Account, Custodial Accounts for P&I and Custodial Accounts for Reserves and of Buydown Funds from the
Buydown Fund Accounts

	
76


	
Section 3.06.  Maintenance of Primary Insurance Policies;
Collections Thereunder

	
78


	
Section 3.07.  Maintenance of Hazard Insurance

	
79


	
Section 3.08.  Enforcement of Due-on-Sale Clauses; Assumption
Agreements

	
79


	
Section 3.09.  Realization Upon Defaulted Mortgage Loans

	
80


	
Section 3.10.  Trustee to Cooperate; Release of Mortgage
Files

	
82


	
Section 3.11.  Compensation to the Master Servicer and the
Servicers

	
83


	
Section 3.12.  Reports to the Trustee; Certificate Account
Statement

	
83


	
Section 3.13.  Annual Statement as to Compliance

	
84


	
Section 3.14.  Access to Certain Documentation and Information
Regarding the Mortgage Loans

	
84


	
Section 3.15.  Annual Independent Public Accountants’
Servicing Report

	
84


	
Section 3.16.  Yield Maintenance Account

	
85


	
Section 3.17.  [Reserved.]

	
85


	
Section 3.18.  [Reserved.]

	
85


	
Section 3.19.  Determination of LIBOR by Master
Servicer.

	
85


	
Section 3.20.  Assumption or Termination of Selling and Servicing
Contracts by Trustee

	
87


	
ARTICLE IV  Payments to Certificateholders; Payment of
Expenses

	
87


	
Section 4.01.  Distributions to Holders of REMIC I Regular
Interests and Class R-1 Residual Interest

	
87


	
Section 4.02.  Advances by the Master Servicer; Distribution
Reports to the Trustee

	
88


	
Section 4.03.  Nonrecoverable Advances

	
89


	
Section 4.04.  Distributions to Certificateholders; Payment of
Special Primary Insurance Premiums

	
90


	
Section 4.05.  Statements to Certificateholders

	
91


	
ARTICLE V  The Certificates

	
92


	
Section 5.01.  The Certificates

	
92


	
Section 5.02.  Certificates Issuable in Classes; Distributions of
Principal and Interest; Authorized Denominations

	
98


	
Section 5.03.  Registration of Transfer and Exchange of
Certificates

	
99


	
Section 5.04.  Mutilated, Destroyed, Lost or Stolen
Certificates

	
99


	
Section 5.05.  Persons Deemed Owners

	
100


	
Section 5.06.  Temporary Certificates

	
100


	
Section 5.07.  Book-Entry for Book-Entry Certificates

	
100


	
Section 5.08.  Notices to Clearing Agency

	
101


	
Section 5.09.  Definitive Certificates

	
101


	
Section 5.10.  Office for Transfer of Certificates

	
102


	
Section 5.11.  Nature of Certificates

	
102


	
ARTICLE VI  The Company and the Master Servicer

	
103


	
Section 6.01.  Liability of the Company and the Master
Servicer

	
103


	
Section 6.02.  Merger or Consolidation of the Company, or the
Master Servicer

	
103


	
Section 6.03.  Limitation on Liability of the Company, the Master
Servicer and Others

	
103


	
Section 6.04.  The Company and the Master Servicer not to
Resign

	
104


	
Section 6.05.  Trustee Access.

	
104


	
ARTICLE VII  Default

	
104


	
Section 7.01.  Events of Default

	
104


	
Section 7.02.  Trustee to Act; Appointment of Successor

	
107


	
Section 7.03.  Notification to Certificateholders

	
108


	
ARTICLE VIII  Concerning the Trustees

	
108


	
Section 8.01.  Duties of Trustees

	
108


	
Section 8.02.  Certain Matters Affecting the Trustees

	
109


	
Section 8.03.  Trustees Not Liable for Certificates or Mortgage
Loans

	
111


	
Section 8.04.  Trustees May Own Certificates

	
111


	
Section 8.05.  The Master Servicer to Pay Trustees’ Fees and
Expenses

	
111


	
Section 8.06.  Eligibility Requirements for Trustees

	
111


	
Section 8.07.  Resignation and Removal of Trustees

	
112


	
Section 8.08.  Successor Trustee

	
113


	
Section 8.09.  Merger or Consolidation of Trustee

	
113


	
Section 8.10.  Appointment of Co-Trustee or Separate
Trustee

	
113


	
Section 8.11.  Authenticating Agents

	
114


	
Section 8.12.  Paying Agents

	
115


	
Section 8.13.  Duties of Delaware Trustee

	
116


	
Section 8.14.  Amendment to Certificate of Trust

	
116


	
Section 8.15.  Yield Maintenance Agreement and Novation
Agreement

	
116


	
ARTICLE IX  Termination

	
117


	
Section 9.01.  Termination Upon Purchase by the Master Servicer or
Liquidation of All Mortgage Loans

	
117


	
Section 9.02.  Additional Termination Requirements

	
119


	
Section 9.03.  Trust Irrevocable

	
119


	
ARTICLE X  Miscellaneous Provisions

	
119


	
Section 10.01.  Amendment

	
119


	
Section 10.02.  Recordation of Agreement

	
121


	
Section 10.03.  Limitation on Rights of
Certificateholders

	
121


	
Section 10.04.  Access to List of Certificateholders

	
122


	
Section 10.05.  Governing Law

	
122


	
Section 10.06.  Notices

	
122


	
Section 10.07.  Severability of Provisions

	
123


	
Section 10.08.  Counterpart Signatures

	
123


	
Section 10.09.  Benefits of Agreement

	
123


	
Section 10.10.  Notices and Copies to Rating Agencies

	
123







 


 


Exhibit A          Form of
Certificates (other than Class R Certificates)


Exhibit B          Form of
Class R Certificates


Exhibit C         
Anti-Predatory Lending Categorization


Exhibit D          Mortgage
Loan Schedule


Exhibit E          
Selling And Servicing Contract


Exhibit F          
Form of Transferor Certificate For Junior Subordinate Certificates


Exhibit G          Form of
Transferee’s Agreement For Junior Subordinate Certificates


Exhibit H          Form of
Additional Matter Incorporated Into The Certificates


Exhibit
I            Transferor Certificate


Exhibit J          
Transferee Affidavit And Agreement


Exhibit K         
[Reserved]


Exhibit L          
Form of Investment Letter


Exhibit M         Form of
Trustee’s Certification Pursuant to Section 2.07


Exhibit N         
Officer’s Certificate With Respect to ERISA Matters Pursuant to Section 5.01(d)


Exhibit O         
Officer’s Certificate With Respect to ERISA Matters Pursuant to Section 5.01(g)


Exhibit P          
Officer’s Certificate With Respect to ERISA Matters Pursuant to Section 5.01(d)




 



This Pooling and Servicing Agreement, dated and effective as of
January 1, 2005 (this “Agreement”), is executed by and among Washington Mutual Mortgage Securities Corp., as
depositor and as Master Servicer (the “Company”), Deutsche Bank National Trust Company, a national banking
association with a corporate trust office at 1761 East St. Andrew Place, Santa Ana, CA 92705, as Trustee (the
“Trustee”), and Deutsche Bank Trust Company Delaware, as Delaware Trustee (the “Delaware
Trustee”).  Capitalized terms used in this Agreement and not otherwise defined have the meanings ascribed to such
terms in Article I hereof.


PRELIMINARY STATEMENT


The Company at the Closing Date is the owner of the Mortgage Loans and
the other property being conveyed by it to the Trust. On the Closing Date, the Company will acquire the REMIC I Regular Interests
and the Class R-1 Residual Interest from the Trust as consideration for its transfer to the Trust of the Mortgage Loans and certain
other assets and will be the owner of the REMIC I Regular Interests and the Class R-1 Residual Interest.  Thereafter on the
Closing Date, the Company will acquire the Certificates (other than the Class R Certificates) and the Class R-2 Residual Interest
from the Trust as consideration for its transfer to the Trust of the REMIC I Regular Interests and will be the owner of the
Certificates.  The Company has duly authorized the execution and delivery of this Agreement to provide for (i) the conveyance
to the Trust of the Mortgage Loans and certain other assets, (ii) the issuance to the Company of the REMIC I Regular Interests and
the Class R-1 Residual Interest representing in the aggregate the entire beneficial interest in REMIC I, (iii) the conveyance to
the Trust of the REMIC I Regular Interests and (iv) the issuance to the Company of the REMIC II Regular Interests and the
Certificates, such REMIC II Regular Interests and the Class R-2 Residual Interest representing in the aggregate the entire
beneficial interest in REMIC II. The Company is entering into this Agreement, and the Trustee and the Delaware Trustee are each
accepting the trust created hereby, for good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged.


The Certificates issued hereunder, other than the Junior Subordinate
and Class Y Certificates, have been offered for sale pursuant to a Prospectus, dated February 10, 2004, and a Prospectus
Supplement, dated January 13, 2005, of the Company (together, the “Prospectus”). The Junior Subordinate
Certificates have been offered for sale pursuant to a Private Placement Memorandum, dated January 18, 2005.  The Trust
created hereunder is intended to be the “Trust” described in the Prospectus and the Private Placement Memorandum and
the Certificates are intended to be the “Certificates” described therein. The following tables set forth the
designation, type of interest, Certificate Interest Rate, initial Class Principal Balance and Final Maturity Date for the REMIC I
Regular Interests, the REMIC II Regular Interests and the Class R Residual Interests:


 









REMIC I
Interests



	
 

	
Class Designation for
each REMIC I Regular Interest and the Class R-1 Residual Interest

	
 

	
Type of Interest

	
 

	
Certificate Interest

Rate (1)

	
 

	
Initial Class

 Principal

 Balance

	
 

	
Final Maturity

 Date*


	
 

	
Class LT1

	
 

	
Regular

	
 

	
Variable (2)

	
 

	
$2,970,961,901.17

	
 

	
January 2045


	
 

	
Class LT2

	
 

	
Regular

	
 

	
Variable (2)

	
 

	
142,010.68

	
 

	
January 2045


	
 

	
Class LT3

	
 

	
Regular

	
 

	
Variable (3)

	
 

	
155,130.74

	
 

	
January 2045


	
 

	
Class LT4

	
 

	
Regular

	
 

	
Variable (4)

	
 

	
155,130.74

	
 

	
January 2045


	
 

	
Class R-1†

	
 

	
Residual

	
 

	
3.724%

	
 

	
100.00

	
 

	
January 2045


	
 

	
 

	
 

	
 

	
 

	
 

	
 

	
 

	
 

	
 


	
*             The Distribution Date in the specified month,
which is the month following the month in which the latest maturing Mortgage Loan matures.  For federal income tax purposes,
for each Class of REMIC I Regular and Residual Interests, the “latest possible maturity date” shall be the Final
Maturity Date.





	
 


	
†              The Class R‐1 Residual Interest
is entitled to receive the applicable Residual Distribution Amount and any Excess Liquidation Proceeds.





	
 


	
(1)           Interest distributed to the REMIC I Regular Interests (other
than the Class LT3 Regular Interest, which shall not be entitled to receive any distributions of interest) and the Class R-1
Residual Interest on each Distribution Date will have accrued at the applicable per annum Certificate Interest Rate on the
applicable Class Principal Balance outstanding immediately before such Distribution Date.





	
 


	
(2)          For each Distribution Date, the Certificate Interest Rate on the
Class LT1 and Class LT2 Regular Interests shall equal the Weighted Average Pass-Through Rate for such Distribution Date.





	
 


	
(3)           The Class LT3 Regular Interest shall not be entitled to
receive any distributions of interest.





	
 


	
(4)           For each Distribution Date, the Certificate Interest Rate on
the Class LT4 Regular Interest shall equal two (2) times the Weighted Average Pass-Through Rate for such Distribution Date.





	
 


											





 


As provided herein, with respect to REMIC I, the Company will cause an
election to be made on behalf of REMIC I to be treated for federal income tax purposes as a REMIC. The REMIC I Regular Interests
will be designated regular interests in REMIC I and the Class R-1 Residual Interest will be designated the sole class of residual
interest in REMIC I, for purposes of the REMIC Provisions.








REMIC II Interests



	
 

	
Class Designation for
each Class of REMIC II Regular Interests and the Class R-2 Residual Interest

	
 

	
Type of Interest

	
 

	
Certificate Interest

Rate (1)

	
 

	
Initial Class

 Principal

 Balance

	
 

	
Final Maturity

 Date*


	
 

	
Class A-1A-L

	
 

	
Regular

	
 

	
Variable (2) (14)

	
 

	
$716,000,000.00

	
 

	
January 2045


	
 

	
Class A-1B-L

	
 

	
Regular

	
 

	
Variable (3) (14)

	
 

	
477,350,000.00

	
 

	
January 2045


	
 

	
Class A-2A1-L

	
 

	
Regular

	
 

	
Variable (4) (14)

	
 

	
764,000,000.00

	
 

	
January 2045


	
 

	
Class A-2A2-L

	
 

	
Regular

	
 

	
Variable (5) (14)

	
 

	
352,300,000.00

	
 

	
January 2045


	
 

	
Class A-2A3-L

	
 

	
Regular

	
 

	
Variable (6) (14)

	
 

	
158,479,000.00

	
 

	
January 2045


	
 

	
Class A-2B-L

	
 

	
Regular

	
 

	
Variable (7) (14)

	
 

	
225,000,000.00

	
 

	
January 2045


	
 

	
Class A-3-L

	
 

	
Regular

	
 

	
Variable (8) (14)

	
 

	
100,000,000.00

	
 

	
January 2045


	
 

	
Class X-L

	
 

	
Regular

	
 

	
Variable (9) (14)

	
 

	
0.00 (10)

	
 

	
January 2045


	
 

	
Class B-1-L

	
 

	
Regular

	
 

	
Variable (11) (14)

	
 

	
65,371,000.00

	
 

	
January 2045


	
 

	
Class B-2-L

	
 

	
Regular

	
 

	
Variable (12) (14)

	
 

	
40,114,000.00

	
 

	
January 2045


	
 

	
Class B-3-L

	
 

	
Regular

	
 

	
Variable (13) (14)

	
 

	
22,285,000.00

	
 

	
January 2045


	
 

	
Class B-4-L

	
 

	
Regular

	
 

	
Variable (13) (14)

	
 

	
20,799,000.00

	
 

	
January 2045


	
 

	
Class B-5-L

	
 

	
Regular

	
 

	
Variable (13) (14)

	
 

	
17,828,000.00

	
 

	
January 2045


	
 

	
Class B-6-L

	
 

	
Regular

	
 

	
Variable (13) (14)

	
 

	
11,888,073.32

	
 

	
January 2045


	
 

	
Class R-2 (15)

	
 

	
Residual

	
 

	
   -----

	
 

	
-----

	
 

	
January 2045


	
 

	
 

	
 

	
 

	
 

	
 

	
 

	
 

	
 

	
 


	
*             The Distribution Date in the specified month,
which is the month following the month in which the latest maturing Mortgage Loan matures.  For federal income tax purposes,
for each Class of REMIC II Regular and Residual Interests, the “latest possible maturity date” shall be the Final
Maturity Date.





	
 


	
(1)           Interest distributed to the REMIC II Regular Interests on
each Distribution Date will have accrued at the applicable per annum Certificate Interest Rate on the applicable Class Principal
Balance (or, in the case of the Class X-L Regular Interest, at the Class X-L Notional Amount) outstanding immediately before such
Distribution Date.





	
 


	
(2)           The Certificate Interest Rate on the Class A-1A-L Regular
Interest for (i) the initial Distribution Date shall equal 2.800%; (ii) each Distribution Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the least
of (a) the Weighted Average Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.320% and (c) 10.50%; and
(iii) each Distribution Date after the Clean-Up Call Option Date, shall equal the least of (a) the Weighted Average
Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.640% and (c) 10.50%. 





	
 


	
(3)           The Certificate Interest Rate on the Class A-1B-L Regular
Interest for (i) the initial Distribution Date shall equal 2.870%; (ii) each Distribution Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the least
of (a) the Weighted Average Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.390% and (c) 10.50%; and
(iii) each Distribution Date after the Clean-Up Call Option Date, shall equal the least of (a) the Weighted Average
Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.780% and (c) 10.50%. 





	
 


	
(4)           The Certificate Interest Rate on the Class A-2A1-L Regular
Interest for (i) the initial Distribution Date shall equal 2.820%; (ii) each Distribution Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the least
of (a) the Weighted Average Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.340% and (c) 10.50%; and
(iii) each Distribution Date after the Clean-Up Call Option Date, shall equal the least of (a) the Weighted Average
Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.680% and (c) 10.50%.  





	
 


	
(5)           The Certificate Interest Rate on the Class A-2A2-L Regular
Interest for (i) the initial Distribution Date shall equal 2.730%; (ii) each Distribution Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the least
of (a) the Weighted Average Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.250% and (c) 10.50%; and
(iii) each Distribution Date after the Clean-Up Call Option Date, shall equal the least of (a) the Weighted Average
Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.500% and (c) 10.50%.





	
 


	
(6)           The Certificate Interest Rate on the Class A-2A3-L Regular
Interest for (i) the initial Distribution Date shall equal 2.880%; (ii) each Distribution Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the least
of (a) the Weighted Average Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.400% and (c) 10.50%; and
(iii) each Distribution Date after the Clean-Up Call Option Date, shall equal the least of (a) the Weighted Average
Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.800% and (c) 10.50%. 





	
 


	
(7)           The Certificate Interest Rate on the Class A-2B-L Regular
Interest for (i) the initial Distribution Date shall equal 2.880%; (ii) each Distribution Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the least
of (a) the Weighted Average Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.400% and (c) 10.50%; and
(iii) each Distribution Date after the Clean-Up Call Option Date, shall equal the least of (a) the Weighted Average
Pass-Through Rate for such Distribution Date, (b) LIBOR plus 0.800% and (c) 10.50%. 





	
 


	
(8)           The Certificate Interest Rate on the Class A-3-L Regular
Interest for (i) the initial Distribution Date shall equal 2.840%; (ii) each Distribution Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the lesser
of (a) the Weighted Average Pass-Through Rate for such Distribution Date and (b) LIBOR plus 0.360%; and (iii) each
Distribution Date after the Clean-Up Call Option Date, shall equal the lesser of (a) the Weighted Average Pass-Through Rate for
such Distribution Date and (b) LIBOR plus 0.720%. 





	
 


	
(9)           For each Distribution Date, the Class X-L Regular Interest
shall accrue interest on the Class X-L Notional Amount.  For each Distribution Date, the Certificate Interest Rate on the
Class X-L Regular Interest shall equal the excess, if any, of (i) the Weighted Average Pass-Through Rate for such Distribution Date
over (ii) the product of (a) the weighted average of the Certificate Interest Rates on the REMIC II Regular Interests (other than
the Class X-L Regular Interest), multiplying the Certificate Interest Rates on the Class A-L Regular Interests by a fraction, the
numerator being the actual number of days in the accrual period and the denominator being 30 and (b) a fraction, the numerator of
which is the aggregate Class Principal Balance of the REMIC II Regular Interests (other than the Class X-L Regular Interest)
immediately before that Distribution Date and the denominator of which is the aggregate principal balance of the Mortgage Loans as
of the second preceding Due Date. 


                For REMIC purposes, the foregoing
rate is equal to a rate per annum equal to the percentage equivalent of a fraction, the numerator of which is the sum of the
amounts calculated pursuant to clauses (1) through (3) below, and the denominator of which is the aggregate Principal Balances of
the REMIC I Regular Interests.  For purposes of calculating the Pass-Through Rate for the Class X Certificates, the numerator
is equal to the sum of the following components:


1.        the Certificate Interest Rate for
REMIC I Regular Interest LT1 minus the related Marker Rate, applied to a notional amount equal to the Class Principal Balance of
REMIC I Regular Interest LT1;


2.        the Certificate Interest Rate for
REMIC I Regular Interest LT2 minus the related Marker Rate, applied to a notional amount equal to the Class Principal Balance of
REMIC I Regular Interest LT2;


3.        the Certificate Interest Rate for
REMIC I Regular Interest LT4 minus twice the related Marker Rate, applied to a notional amount equal to the Class Principal Balance
of REMIC I Regular Interest LT4.


 

	
 


	
(10)         The Class X-L Regular
Interest shall have both a Class Notional Amount and a Class Principal Balance. The Class X-L Principal Balance shall initially
equal zero and shall thereafter be increased by the portion, if any, of Net Negative Amortization Amounts allocated to the Class
X-L Regular Interest pursuant to the definition of “Net Negative Amortization Amount.”  Interest shall accrue on
the Class X-L Notional Amount and shall not accrue on the Class X-L Principal Balance. Principal shall not be payable with respect
to the Class X-L Notional Amount.





	
 


	
(11)         The Certificate Interest Rate on the Class B-1-L Regular Interest for
(i) the initial Distribution Date shall equal 3.030%; (ii) each Distribution Date, other than the initial Distribution
Date, on or before the Clean-Up Call Option Date, shall equal the lesser of (a) the Weighted Average Pass-Through Rate for such
Distribution Date and (b) LIBOR plus 0.550%; and (iii) each Distribution Date after the Clean-Up Call Option Date, shall
equal the lesser of (a) the Weighted Average Pass-Through Rate for such Distribution Date and (b) LIBOR plus 0.825%.





	
 


	
(12)         The Certificate Interest Rate on the Class B-2-L Regular Interest for
(i) the initial Distribution Date shall equal 3.430%; (ii) each Distribution Date, other than the initial Distribution
Date, on or before the Clean-Up Call Option Date, shall equal the lesser of (a) the Weighted Average Pass-Through Rate for such
Distribution Date and (b) LIBOR plus 0.950%; and (iii) each Distribution Date after the Clean-Up Call Option Date, shall
equal the lesser of (a) the Weighted Average Pass-Through Rate for such Distribution Date and (b) LIBOR plus 1.425%.





	
 


	
(13)         The Certificate Interest Rate on the Class B-3-L, Class B-4-L, Class
B-5-L and Class B-6-L Regular Interests for (i) the initial Distribution Date shall equal 3.580%; (ii) each Distribution
Date, other than the initial Distribution Date, on or before the Clean-Up Call Option Date, shall equal the lesser of (a) the
Weighted Average Pass-Through Rate for such Distribution Date and (b) LIBOR plus 1.100%; and (iii) each Distribution Date
after the Clean-Up Call Option Date, shall equal the lesser of (a) the Weighted Average Pass-Through Rate for such Distribution
Date and (b) LIBOR plus 1.650%.





	
 


	
(14)         For any Distribution Date, interest distributable to the Class A, Class
B and Class X Certificates may not equal interest accrued at the Certificate Interest Rates for the Corresponding Classes of REMIC
II Regular Interests.  For any Distribution Date from and including March 2005 to and including August 2013, interest may
be distributable to some Classes of Class A Certificates in an amount greater than interest accrued at the Certificate Interest
Rate for the Corresponding Class of REMIC II Regular Interests, and interest may be distributable to the Class X Certificates in an
amount less than interest accrued at the Certificate Interest Rate for the Class X-L Regular Interest, in each case pursuant to the
second sentence of Section 4.04(a).





	
 


	
(15)         The Class R‐2 Residual Interest shall be entitled to receive the
applicable Residual Distribution Amount.  The Class R‐2 Residual Interest shall not be entitled to receive any
distributions of interest or principal.

	
 


	
 

	
 


											





As provided herein, with respect to REMIC II, the Company will cause
an election to be made on behalf of REMIC II to be treated for federal income tax purposes as a REMIC.  The REMIC II Regular
Interests will be designated regular interests in REMIC II and the Class R-2 Residual Interest will be designated the sole class of
residual interest in REMIC II, for purposes of the REMIC Provisions.


In addition, the Trust will issue the Class R Certificates, which will
represent ownership of the Class R-1 and Class R-2 Residual Interests.


In addition, the Trust will issue the Class A and Class B
Certificates, each of which Class will represent ownership of (i) the Corresponding Class of REMIC II Regular Interests and
(ii) the applicable rights specified in the second sentence of Section 4.04(a), and will issue the Class X Certificates,
which will represent ownership of (i) the Class X-L Regular Interest and (ii) the obligations specified in the second sentence
of Section 4.04(a).


In addition, the Trust will issue the Class Y Certificates, which will
not have a Class Principal Balance and will only be entitled to receive on any Distribution Date the excess, if any, of (i) amounts
received pursuant to the Yield Maintenance Agreement for that Distribution Date and (ii) the portion thereof payable to the Class A
Certificates on that Distribution Date.  The Class Y Certificates will not represent an interest in any REMIC.


As of the Cut-Off Date, the Mortgage Loans have an aggregate Principal
Balance of $2,971,414,173.32 and the Certificates have an Aggregate Certificate Principal Balance of $2,971,414,173.32.


W I T N E S S E T H :


WHEREAS, the Company is a corporation duly organized and existing
under and by virtue of the laws of the State of Delaware and has full corporate power and authority to enter into this Agreement
and to undertake the obligations undertaken by it herein;


WHEREAS, the Trustee is a national banking association duly organized
and existing under the laws of the United States of America and has full power and authority to enter into this
Agreement;


WHEREAS, the Delaware Trustee is a banking corporation duly organized
and existing under the laws of the State of Delaware and has full power and authority to enter into this Agreement;


WHEREAS, prior to the execution and delivery hereof, the Company and
the Delaware Trustee have entered into the Original Trust Agreement, and the Delaware Trustee has filed the Certificate of
Trust;


WHEREAS, it is the intention of the Company, the Trustee and the
Delaware Trustee that the Trust created by this Agreement constitute a statutory trust under the Statutory Trust Statute, that this
Agreement constitute the governing instrument of the Trust, and that this Agreement amend and restate the Original Trust
Agreement;


WHEREAS, the Company is the owner of the Mortgage Loans identified in
the Mortgage Loan Schedule hereto having unpaid Principal Balances on the Cut-Off Date as stated therein; and


WHEREAS, the Company has been duly authorized to create the Trust to
(i) hold the Mortgage Loans and certain other property, (ii) issue the REMIC I Regular Interests and the Class R-1 Residual
Interest, (iii) hold the REMIC I Regular Interests and (iv) issue the REMIC II Regular Interests and the Certificates.


NOW, THEREFORE, in order to declare the terms and conditions upon
which the REMIC I Regular Interests, the REMIC II Regular Interests, the Class R Residual Interests and the Certificates are to be
issued, and in consideration of the premises and of the purchase and acceptance of the Certificates by the Holders thereof, the
Company covenants and agrees with the Trustee and the Delaware Trustee, for the equal and proportionate benefit of the respective
Holders from time to time of the REMIC I Regular Interests, the REMIC II Regular Interests and the Certificates, as applicable, as
follows:


ARTICLE I


Section 1.01.        Definitions.


Whenever used in this Agreement, the following words and phrases,
unless the context otherwise requires, shall have the following meanings:


Adjusted
Cap Rate:  For any Distribution Date and any Class of Class A-L or Class B-L
Regular Interests, a fraction, the numerator of which is equal to the product of (i) the amount of interest distributions accrued
on the Mortgage Loans on the basis of the Weighted Average Pass-Through Rate for that Distribution Date less the Net Negative
Amortization and (ii) 12, and the denominator of which is equal to the Stated Principal Balance of the Mortgage Loans as of the
second preceding Due Date after giving effect to the payments due on the Mortgage Loans on that Due Date multiplied, for the Class
A Certificates by a ratio, the numerator of which is 30 and the denominator of which is the actual number of days in the related
accrual period. 


For any Distribution Date
and the Class X-L Regular Interest and the Certificate Interest Rate for the Class X Certificates, computed for this purpose by
(i) reducing the Weighted Average Pass-Through Rate for that Distribution Date by a per annum rate equal to a fraction, the
numerator of which is the Net Negative Amortization multiplied by 12, and the denominator of which is equal to the Stated Principal
Balance of the Mortgage Loans as of the second preceding Due Date after giving effect to the payments due on the Mortgage Loans on
that Due Date and (ii) substituting “Adjusted Cap Rate” for “Weighted Average Pass-Through Rate” in
clause (a) in the calculation of Certificate Interest Rate for each of notes (2) through (9) and (11) through (13) to the
table entitled “REMIC II Interests” in the Preliminary Statement hereto.


Aggregate Certificate Principal
Balance:  At any given time, the sum of the then current Class Principal
Balances of the Certificates.


Appraised Value:  With respect to any (i) Mortgage Loan that is not a Streamlined Mortgage Loan or ROV Mortgage Loan, the
lesser of (a) the value set forth on the appraisal made in connection with the origination of the related Mortgage Loan as the
value of the related Mortgaged Property and (b) the purchase price paid for the Mortgaged Property, provided,
however, that if such Mortgage Loan was originated in connection with the refinance of a mortgage loan, such value shall be
based solely on the appraisal made in connection with the origination of such Mortgage Loan; (ii) ROV Mortgage Loan, the
lesser of (a) the value set forth on the residential appraisal review made in connection with the origination of the related
Mortgage Loan as the value of the related Mortgaged Property and (b) the purchase price paid for the Mortgaged Property,
provided, however, that if such ROV Mortgage Loan was originated in connection the refinance of a mortgage loan, such
value shall be based solely on the residential appraisal review made in connection with the origination of such ROV Mortgage Loan;
and (iii) Streamlined Mortgage Loan, the value set forth in the appraisal made in connection with the origination of the
mortgage loan being refinanced.


Assignment of Proprietary Lease:  With respect to a Cooperative Loan, the assignment or mortgage of the related Cooperative Lease
from the Mortgagor to the originator of the Cooperative Loan.


Authenticating Agent:  Any authenticating agent appointed by the Trustee pursuant to Section 8.11.


Authorized Denomination:  With respect to each Class of Certificates (other than the Class X and Class R Certificates), an
initial Certificate Principal Balance equal to $25,000 and multiples of $1 in excess thereof, except that one Certificate of each
Class of the Junior Subordinate Certificates may be issued in an amount that is not an integral multiple of $1.  With respect
to the Class X Certificates, a Class Notional Amount as of the Cut-Off Date equal to $100,000 and multiples of $1 in excess
thereof.  With respect to the Class R Certificates, one Certificate with a Percentage Interest equal to 0.01% and one
Certificate with a Percentage Interest equal to 99.99%.


Bankruptcy Loss:  A loss on a Mortgage Loan arising out of (i) a reduction in the Minimum Monthly Payment for such Mortgage Loan by
a court of competent jurisdiction in a case under the United States Bankruptcy Code, other than any such reduction that arises out
of clause (ii) of this definition of “Bankruptcy Loss,” including, without limitation, any such reduction that results
in a permanent forgiveness of principal, or (ii) with respect to any Mortgage Loan, a valuation, by a court of competent
jurisdiction in a case under such Bankruptcy Code, of the related Mortgaged Property in an amount less than the then outstanding
Principal Balance of such Mortgage Loan.


Beneficial Holder:  A Person holding a beneficial interest in any Book-Entry Certificate as or through a DTC Participant or an
Indirect DTC Participant or a Person holding a beneficial interest in any Definitive Certificate.


Benefit Plan Opinion:  With respect to any Certificate presented for registration in the name of any Person, an Opinion of Counsel
acceptable to and in form and substance satisfactory to the Trustee and the Company to the effect that the purchase or holding of
such Certificate is permissible under applicable law, will not constitute or result in a non-exempt prohibited transaction under
Section 406 of ERISA or Section 4975 of the Code, and will not subject the Trust, the Trustee, the Delaware Trustee, the Master
Servicer or the Company to any obligation or liability (including obligations or liabilities under Section 406 of ERISA or Section
4975 of the Code) in addition to those undertaken in this Agreement, which Opinion of Counsel shall not be an expense of the Trust,
the Trustee, the Delaware Trustee, the Master Servicer or the Company.


Book-Entry Certificates:  The Class A, Class X and Senior Subordinate Certificates, beneficial ownership and transfers of which
shall be made through book entries as described in Section 5.07.


Business Day:  Any day other than a Saturday or a Sunday or a day on which banking institutions in Stockton, California, Chicago,
Illinois, New York, New York, Seattle, Washington or any city in which the Corporate Trust Office is located (which shall initially
be Santa Ana, California) are authorized or obligated by law or executive order to be closed.


Buydown Agreement:  An agreement between a Person and a Mortgagor pursuant to which such Person has provided a Buydown
Fund.


Buydown Fund:  A fund provided by the originator of a Mortgage Loan or another Person with respect to a Buydown Loan which
provides an amount sufficient to subsidize regularly scheduled principal and interest payments due on such Buydown Loan for a
period.  Buydown Funds may be (i) funded at the par values of future payment subsidies, or (ii) funded in an amount less
than the par values of future payment subsidies, and determined by discounting such par values in accordance with interest accruing
on such amounts, in which event they will be deposited in an account bearing interest. Buydown Funds may be held in a separate
Buydown Fund Account or may be held in a Custodial Account for P&I or a Custodial Account for Reserves and monitored by a
Servicer.


Buydown Fund Account:  A separate account or accounts created and maintained pursuant to Section 3.02 (a) with a financial
institution approved by the Master Servicer, (b) within FDIC insured accounts (or other accounts with comparable insurance coverage
acceptable to the Rating Agencies) created, maintained and monitored by a Servicer or (c) in a separate non-trust account without
FDIC or other insurance in an Eligible Institution (including the Trustee). Such account or accounts may be non-interest bearing or
may bear interest. In the event that a Buydown Fund Account is established pursuant to clause (b) of the preceding sentence,
amounts held in such Buydown Fund Account shall not exceed the level of deposit insurance coverage on such account; accordingly,
more than one Buydown Fund Account may be established.


Buydown Loan:  A Mortgage Loan for which the Mortgage Interest Rate has been subsidized through a Buydown Fund provided at the
time of origination of such Mortgage Loan.


Cap Strike Rate:  For any Distribution Date, the amount set forth under the heading “Strike Rate” in
Schedule 1 of the Prospectus.


Carry-Forward Subsequent Recoveries
Amount:  For any Distribution Date, the excess, if any,
of (i) the Subsequent Recoveries for such Distribution Date over (ii) the amount by which the Class Principal Balance of the Class
of Subordinate Certificates with the lowest priority is increased in respect of Subsequent Recoveries on such Distribution Date
pursuant to the definition of “Class Principal Balance” herein.


Carryover Shortfall Amount:  For any Distribution Date and for any Class of Class A Certificates (other than the
Class A-3 Certificates), the sum of: (i) the excess, if any, of (a) the amount of interest that would have accrued on
the Class Principal Balance of such Class’ Corresponding Class immediately before such Distribution Date, during the No-Delay
Accrual Period, at a Certificate Interest Rate equal to the lesser of (1) LIBOR plus the related margin for
such Class for such Distribution Date (as specified in the applicable note to the table entitled
“REMIC II Interests” in the Preliminary Statement hereto) and (2) 10.50%, over (b) the amount of interest that
accrued on such Class Principal Balance, during the No-Delay Accrual Period, at the actual Certificate Interest
Rate for such Class for such Distribution Date, (ii) the portion of the amount described in clause (i) above remaining unpaid from
prior Distribution Dates, and (iii) one month’s interest at the Certificate Interest Rate described in clause (i)(a) above on
the amount described in clause (ii) above.


Carryover Shortfall Payment:  For any Class of Class A Certificates (other than
the Class A-3 Certificates) for any Distribution Date, the lesser of (a) the Carryover Shortfall Amount for such Class for
such Distribution Date reduced by the Yield Maintenance Payment for such Class for such Distribution Date and (b) such
Class’ pro rata share of the Interest Distribution Amount for the Class X-L Regular Interest for such
Distribution Date (such pro rata share calculated based on an allocation of such Interest Distribution Amount among the Classes of Class A Certificates (other than the
Class A-3 Certificates) pro rata according to Carryover Shortfall Amount for such Distribution
Date).


Certificate:  Any one of the Certificates issued pursuant to this Agreement, executed by the Trustee and authenticated by or on
behalf of the Trustee hereunder in substantially one of the forms set forth in Exhibit A and B hereto. The additional matter
appearing in Exhibit H shall be deemed incorporated into Exhibit A as though set forth at the end of such Exhibit.


Certificate Account:  The separate trust account created and maintained with the Trustee, the Investment Depository or any other
bank or trust company acceptable to the Rating Agencies which is incorporated under the laws of the United States of America or any
state thereof pursuant to Section 3.04, which account shall bear a designation clearly indicating that the funds deposited therein
are held in trust for the benefit of the Trust or any other account serving a similar function acceptable to the Rating Agencies.
Funds in the Certificate Account may be invested in Eligible Investments pursuant to Section 3.04(b) and reinvestment earnings
thereon shall be paid to the Master Servicer as additional servicing compensation. Funds deposited in the Certificate Account
(exclusive of the Master Servicing Fee) shall be held in trust for the Certificateholders and for the uses and purposes set forth
in Section 2.01, Section 3.04, Section 3.05, Section 4.01 and Section 4.04.


Certificateholder or Holder:  With respect to the Certificates, the Person in whose name a Certificate is registered in the
Certificate Register, except that, solely for the purposes of giving any consent pursuant to this Agreement, any Certificate
registered in the name of the Company, the Master Servicer or any affiliate thereof shall be deemed not to be outstanding and the
Percentage Interest evidenced thereby shall not be taken into account in determining whether the requisite percentage of Percentage
Interests necessary to effect any such consent has been obtained; provided, that the Trustee may conclusively rely upon an
Officer’s Certificate to determine whether any Person is an affiliate of the Company or the Master Servicer.  With
respect to the REMIC I Regular Interests, the owner of the REMIC I Regular Interests, which as of the Closing Date shall be the
Trust.  With respect to each Class of REMIC II Regular Interests, the Holder of the Corresponding Class of
Certificates.


Certificate Interest Rate:  For each Class of REMIC I Regular Interests and REMIC II Regular Interests and the Class R-1 Residual
Interest, the per annum rate set forth as the Certificate Interest Rate for such Class in the Preliminary Statement
hereto.


Certificate of Trust:  The certificate of trust filed with respect to the Trust with the Secretary of State in accordance with
Section 3810(a) of the Statutory Trust Statute.


Certificate Principal Balance:  For each Certificate of any Class, the portion of the related Class Principal Balance, if any,
represented by such Certificate; provided, however, that each Class X Certificate will represent a portion of the
Class X Principal Balance equal to its Percentage Interest in the Class X-L Notional Amount.


Certificate Register and Certificate
Registrar:  The register maintained and the registrar appointed,
respectively, pursuant to Section 5.03.


Class:  All REMIC I Regular Interests or the Class R-1 Residual Interest having the same priority and rights to payments on the
Mortgage Loans from the REMIC I Available Distribution Amount, and all REMIC II Regular Interests or the Class R-2 Residual
Interest having the same priority and rights to payments on the REMIC I Regular Interests from the REMIC II Available Distribution
Amount, as applicable, which REMIC I Regular Interests, REMIC II Regular Interests and Class R Residual Interests, as applicable,
shall be designated as a separate Class, and which, in the case of the Certificates (including the Class R Certificates
representing ownership of the Class R Residual Interests), shall be set forth in the applicable forms of Certificates attached
hereto as Exhibits A and B.  Each Class of REMIC I Regular Interests and the Class R-1 Residual Interest shall be
entitled to receive the amounts allocated to such Class pursuant to the definition of “REMIC I Distribution Amount”
only to the extent of the REMIC I Available Distribution Amount for such Distribution Date remaining after distributions in
accordance with prior clauses of the definition of “REMIC I Distribution Amount” and each Class of REMIC II Regular
Interests and the Class R-2 Residual Interest shall be entitled to receive the amounts allocated to such Class pursuant to the
definition of “REMIC II Distribution Amount” only to the extent of the REMIC II Available Distribution Amount for such
Distribution Date remaining after distributions in accordance with prior clauses of the definition of “REMIC II Distribution
Amount.”  The Class Y Certificates shall only be entitled to receive on any Distribution Date certain amounts received
pursuant to the Yield Maintenance Agreement as specified in Section 4.04(a).


In addition to their rights to receive payments from the REMIC II
Available Distribution Amount on their Corresponding Class of REMIC II Regular Interests, the Class A Certificates shall be
entitled to receive payments, if any, as specified in the second sentence of Section 4.04(a).  Notwithstanding the right of
the Class X Certificates to receive payments from the REMIC II Available Distribution Amount on the Class X-L Regular Interest, the
amount of such payments may be reduced as specified in the second sentence of Section 4.04(a).


Class A Certificates:  The Class A-1A, Class A-1B, Class A-2A1, Class A-2A2, Class A-2A3, Class A-2B and Class A-3
Certificates.


Class A-L Regular Interests:  The Class A-1A-L, Class A-1B-L, Class A-2A1-L, Class A-2A2-L, Class A-2A3-L, Class A-2B-L and
Class A-3-L Regular Interests.


Class A-1A Certificates:  The Certificates. designated as “Class A-1A” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class A-1A-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class A-1B Certificates:  The Certificates. designated as “Class A-1B” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class A-1B-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class A-2A1 Certificates:  The Certificates. designated as “Class A-2A1” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class A-2A1-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class A-2A2 Certificates:  The Certificates. designated as “Class A-2A2” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class A-2A2-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class A-2A3 Certificates:  The Certificates. designated as “Class A-2A3” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class A-2A3-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class A-2B Certificates:  The Certificates. designated as “Class A-2B” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class A-2B-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class A-3 Certificates:  The Certificates. designated as “Class A-3” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class A-3-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class B Certificates: The Class B-1, Class B-2, Class B-3, Class B-4, Class B-5 and Class B-6 Certificates.


Class B-L Regular Interests:  The Class B-1-L, Class B-2-L, Class B-3-L, Class B-4-L, Class B-5-L and Class B-6-L Regular
Interests.


Class B-1 Certificates:  The Certificates designated as “Class B-1” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class B-1-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class B-2 Certificates:  The Certificates designated as “Class B-2” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class B-2-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class B-3 Certificates:  The Certificates designated as “Class B-3” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class B-3-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class B-4 Certificates:  The Certificates designated as “Class B-4” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class B-4-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class B-5 Certificates:  The Certificates designated as “Class B-5” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class B-5-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class B-6 Certificates:  The Certificates designated as “Class B-6” on the face thereof in substantially the form
attached hereto as Exhibit A.


Class B-6-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II
Regular Interest and is entitled to distributions as set forth herein.


Class LT Principal Reduction Amounts:  For any Distribution Date, the amounts by which the Class Principal Balances of the
Class LT1, Class LT2, Class LT3 and Class LT4 Regular Interests, respectively, will be reduced on such Distribution Date by the
allocation of Realized Losses and the distribution of principal, determined as described in Appendix 1.


Class LT Regular Interests: The Class LT1, Class LT2, Class LT3 and Class LT4 Regular Interests.


Class LT1 Regular Interest: The uncertificated undivided beneficial interest in REMIC I which constitutes a REMIC I Regular Interest and
is entitled to distributions as set forth herein.


Class LT2 Principal Distribution
Amount:  For any Distribution Date, the excess, if any, of the Class
LT2 Principal Reduction Amount for such Distribution Date over the principal portion of Realized Losses allocated to the Class LT2
Regular Interest on such Distribution Date.


Class LT2 Regular Interest: The uncertificated undivided beneficial interest in REMIC I which constitutes a REMIC I Regular Interest and
is entitled to distributions as set forth herein.


Class LT3 Principal Distribution
Amount:  For any Distribution Date, the excess, if any, of the Class
LT3 Principal Reduction Amount for such Distribution Date over the principal portion of Realized Losses allocated to the Class LT3
Regular Interest on such Distribution Date.


Class LT3 Regular Interest: The uncertificated undivided beneficial interest in REMIC I which constitutes a REMIC I Regular Interest and
is entitled to distributions as set forth herein.


Class LT4 Principal Distribution
Amount:  For any Distribution Date, the excess, if any, of the Class
LT4 Principal Reduction Amount for such Distribution Date over the principal portion of Realized Losses allocated to the Class LT4
Regular Interest on such Distribution Date.


Class LT4 Regular Interest: The uncertificated undivided beneficial interest in REMIC I which constitutes a REMIC I Regular Interest and
is entitled to distributions as set forth herein.


Class Notional Amount:  With respect to the Class X Certificates and the Class X-L Regular Interest, the Class X-L Notional
Amount.


Class Principal Balance:  For any Class of REMIC I or REMIC II Regular Interests and for the Class R-1 Residual Interest, the
applicable initial Class Principal Balance therefor set forth in the Preliminary Statement hereto (or, in the case of the Class R
Certificates, the Class Principal Balance of the Class R-1 Residual Interest), corresponding to the rights of such Class in
payments of principal due to be passed through to such Class from principal payments on the Mortgage Loans or the REMIC I Regular
Interests, as applicable, as reduced from time to time by (x) distributions of principal to such Class and (y) the portion of
Realized Losses allocated to the Class Principal Balance of such Class pursuant to the definition of “Realized Loss”
with respect to a given Distribution Date, and as increased from time to time by the portion of Net Negative Amortization Amounts
allocated to the Class Principal Balance of such Class pursuant to the definition of “Net Negative Amortization Amount”
with respect to a given Distribution Date; and for any Class of Certificates, the Class Principal Balance of the Corresponding
Class of REMIC II Regular Interests.  For any Distribution Date, the reduction of the Class Principal Balance of any Class of
Certificates and REMIC I or REMIC II Regular Interests pursuant to the definition of “Realized Loss” and the increase
in the Class Principal Balance of any Class of Certificates and REMIC I or REMIC II Regular Interests pursuant to the definition of
“Net Negative Amortization Amount” shall be deemed effective after the determination and distribution of principal on
such Class pursuant to the definitions of “REMIC I Distribution Amount” and “REMIC II Distribution
Amount.”


Notwithstanding the foregoing, (A) any amounts distributed in respect
of principal losses pursuant to paragraph (I)(xxi) of the definition of “REMIC II Distribution Amount” shall not cause
a reduction in the Class Principal Balances of the REMIC II Regular Interests or their Corresponding Classes and (B) any amounts
distributed in respect of principal losses pursuant to clause (v) of the definition of “REMIC I Distribution
Amount” shall not cause a reduction in the Class Principal Balances of the REMIC I Regular Interests. 


In addition to the foregoing, on each Distribution Date, the Class
Principal Balance of the Class of Subordinate Certificates with the lowest priority then outstanding (and its Corresponding Class
of REMIC II Regular Interests) shall be increased by an amount equal to the lesser of (i) the Subsequent Recoveries for such
Distribution Date and (ii) the amount of Realized Losses allocated to such Class on previous Distribution Dates (the amount in this
clause (ii) reduced by the amount, if any, by which such Class Principal Balance has been increased on prior Distribution Dates
pursuant to this paragraph).


The Class Principal Balance for the Class A-1A Certificates shall be
referred to as the “Class A-1A Principal Balance,” the Class Principal Balance for the Class A-1A-L Regular Interest
shall be referred to as the “Class A-1A-L Principal Balance” and so on.  The Class Principal Balances for the
Class X Certificates and the Class X-L Regular Interest shall be zero as of the Closing Date and shall increase after the Closing
Date by the portion, if any, of Net Negative Amortization Amounts allocated to the Class X-L Regular Interest pursuant to the
definition of “Net Negative Amortization Amount”.


Class R Certificates:  The Certificates designated as “Class R” on the face thereof in substantially the form attached
hereto as Exhibit B, representing ownership of the Class R-1 and Class R-2 Residual Interests, each of which Class of Residual
Interests has been designated as the sole class of “residual interest” in REMIC I and REMIC II, respectively, pursuant
to Section 2.06 and Section 2.11, respectively, for purposes of Section 860G(a)(2) of the Code.


Class R Residual Interests:  The Class R-1 and Class R-2 Residual Interests (which shall be transferable only as a unit evidenced by
the Class R Certificates, in accordance with the applicable provisions of Section 5.01).


Class R-1 Residual Interest:  The uncertificated undivided
beneficial interest in REMIC I which has been designated as the single class of “residual interest” in REMIC I pursuant
to Section 2.06.  The Class R-1 Residual Interest, together with the REMIC I Regular Interests, shall be deemed to be a
separate series of beneficial interests in the assets of the Trust consisting of the REMIC I Assets pursuant to Section 3806(b)(2)
of the Statutory Trust Statute.


Class R-2 Residual Interest:  The uncertificated undivided beneficial interest in REMIC II which has been designated as the
single class of “residual interest” in REMIC II pursuant to Section 2.11.  The Class R-2 Residual Interest,
together with the REMIC II Regular Interests, shall be deemed to be a separate series of beneficial interests in the assets of the
Trust consisting of the REMIC II Assets pursuant to Section 3806(b)(2) of the Statutory Trust Statute.


Class X Certificates:  The Certificates designated as “Class X” on the face thereof in substantially the form attached
hereto as Exhibit A.


Class X-L Notional Amount:  For any Distribution Date, the aggregate principal balance of the Mortgage Loans as of the second
preceding Due Date after giving effect to the payments due on the Mortgage Loans on that Due Date.


Class X-L Regular Interest:  The uncertificated undivided beneficial interest in REMIC II which constitutes a REMIC II Regular
Interest and is entitled to distributions as set forth herein.


Class Y Certificates:  The Certificates designated as “Class Y” on the face thereof in substantially the form attached
hereto as Exhibit A.


Clean-Up Call Option Date:  The date on which the aggregate principal balance of the Mortgage Loans has been reduced to less than
the Clean-Up Call Percentage of that balance as of the Cut-Off Date.


Clean-Up Call Percentage:  10%.


Clearing Agency:  An organization registered as a “clearing agency” pursuant to Section 17A of the Securities Exchange
Act of 1934, as amended, which initially shall be DTC.


Closing Date:  January 18, 2005, which is the date of settlement of the sale of the Certificates to the original purchasers
thereof.


Code:  The Internal Revenue Code of 1986, as amended.


Company:  Washington Mutual Mortgage Securities Corp., a Delaware corporation, or its successor-in-interest.


Compensating Interest: For any Distribution Date, the least of (i) the sum of (a) the aggregate Master Servicing Fee payable with
respect to the Mortgage Loans on such Distribution Date, (b) the aggregate Payoff Earnings with respect to the Mortgage Loans for
such Distribution Date and (c) the aggregate Payoff Interest with respect to the Mortgage Loans for such Distribution Date; (ii)
the aggregate Uncollected Interest with respect to the Mortgage Loans for such Distribution Date and (iii) 1/12 of 0.125% of
the aggregate Principal Balance of the Mortgage Loans immediately preceding such Distribution Date.


Cooperative:  A private, cooperative housing corporation which owns or leases land and all or part of a building or buildings,
including apartments, spaces used for commercial purposes and common areas therein and whose board of directors authorizes, among
other things, the sale of Cooperative Stock.


Cooperative Apartment:  A dwelling unit in a multi-dwelling building owned or leased by a Cooperative, which unit the Mortgagor has
an exclusive right to occupy pursuant to the terms of a proprietary lease or occupancy agreement.


Cooperative Lease:  With respect to a Cooperative Loan, the proprietary lease or occupancy agreement with respect to the
Cooperative Apartment occupied by the Mortgagor and relating to the related Cooperative Stock, which lease or agreement confers an
exclusive right to the holder of such Cooperative Stock to occupy such apartment.


Cooperative Loans:  Any of the Mortgage Loans made in respect of a Cooperative Apartment, evidenced by a Mortgage Note and
secured by (i) a Security Agreement, (ii) the related Cooperative Stock Certificate, (iii) an assignment or mortgage of the
Cooperative Lease, (iv) financing statements and (v) a stock power (or other similar instrument), and ancillary thereto, a
Recognition Agreement, each of which was transferred and assigned to the Trust pursuant to Section 2.04.


Cooperative Stock:  With respect to a Cooperative Loan, the single outstanding class of stock, partnership interest or other
ownership instrument in the related Cooperative.


Cooperative Stock Certificate:  With respect to a Cooperative Loan, the stock certificate or other instrument evidencing the
related Cooperative Stock.


Corporate Trust Office:  The corporate trust office of the Trustee in the State of California, at which at any particular time its
corporate trust business with respect to this Agreement shall be administered, which office at the date of the execution of this
Agreement is located at 1761 East St. Andrew Place, Santa Ana, CA 92705, Attention: Trust Administration WA05A1.


Corporation:  Any Person (other than an individual, partnership, joint venture or unincorporated organization) incorporated,
associated, organized, chartered or existing under the laws of any state or under the federal laws of the United States of America;
provided, that such Person have indefinite existence under the law of its domicile.


Corresponding Class:  With respect to the Class A, Class X and Class B Certificates and the REMIC II Regular Interests, the
“Corresponding Class” shall be as indicated in the following table:



	
Class
A-1A-L

	
 

	
 

	
Class A-1A


	
Class
A-1B-L

	
 

	
 

	
Class A-1B


	
Class
A-2A1-L

	
 

	
 

	
Class
A-2A1


	
Class
A-2A2-L

	
 

	
 

	
Class
A-2A2


	
Class
A-2A3-L

	
 

	
 

	
Class
A-2A3


	
Class
A-2B-L

	
 

	
 

	
Class A-2B


	
Class
A-3-L

	
 

	
 

	
Class A-3


	
Class X-L

	
 

	
 

	
Class X


	
Class
B-1-L

	
 

	
 

	
Class B-1


	
Class
B-2-L

	
 

	
 

	
Class B-2


	
Class
B-3-L

	
 

	
 

	
Class B-3


	
Class
B-4-L

	
 

	
 

	
Class B-4


	
Class
B-5-L

	
 

	
 

	
Class B-5


	
Class B-6-L

	
 

	
 

	
Class B-6







 


Credit Support Depletion Date:  The first Distribution Date on which the aggregate Class Principal Balance of the Class B
Certificates has been or will be reduced to zero as a result of principal distributions thereon and the allocation of Realized
Losses on such Distribution Date.


Cumulative Carry-Forward Subsequent Recoveries
Amount:  For any Distribution Date, the sum of (i) the
Carry-Forward Subsequent Recoveries Amount for such Distribution Date and (ii) the Carry-Forward Subsequent Recoveries Amounts for
prior Distribution Dates to the extent such Carry-Forward Subsequent Recoveries Amounts have not been applied in reduction of
Realized Losses on prior Distribution Dates pursuant to the first paragraph of the definition of “Realized Loss”
herein.


Curtailment:  Any payment of principal on a Mortgage Loan made by or on behalf of the related Mortgagor, other than a Minimum
Monthly Payment, a Prepaid Monthly Payment or a Payoff, which is applied to reduce the outstanding principal balance of the
Mortgage Loan.  (Prepayment penalties are not payments of principal and hence Curtailments do not include prepayment
penalties).


Curtailment Shortfall:  For any Distribution Date and for any Curtailment applied with a Monthly Payment in the Prior Period other
than a Prepaid Monthly Payment, an amount equal to one month’s interest on such Curtailment at the applicable Pass-Through
Rate on such Mortgage Loan.


Custodial Account for P&I:  The Custodial Account for principal and interest established and maintained by each Servicer
pursuant to its Selling and Servicing Contract and caused by the Master Servicer to be established and maintained pursuant to
Section 3.02 (a) with a financial institution approved by the Master Servicer such that the rights of the Master Servicer, the
Trust, the Trustee, the Delaware Trustee and the Certificateholders thereto shall be fully protected against the claims of any
creditors of the applicable Servicer and of any creditors or depositors of the institution in which such account is maintained, (b)
within FDIC insured accounts (or other accounts with comparable insurance coverage acceptable to the Rating Agencies) created,
maintained and monitored by a Servicer or (c) in a separate non-trust account without FDIC or other insurance in an Eligible
Institution (including the Trustee). In the event that a Custodial Account for P&I is established pursuant to clause (b) of the
preceding sentence, amounts held in such Custodial Account for P&I shall not exceed the level of deposit insurance coverage on
such account; accordingly, more than one Custodial Account for P&I may be established. Any amount that is at any time not
protected or insured in accordance with the first sentence of this definition of “Custodial Account for P&I” shall
promptly be withdrawn from such Custodial Account for P&I and be remitted to the Investment Account.


Custodial Account for Reserves:  The Custodial Account for Reserves established and maintained by each Servicer pursuant to its
Selling and Servicing Contract and caused by the Master Servicer to be established and maintained pursuant to Section 3.02 (a) with
a financial institution approved by the Master Servicer such that the rights of the Master Servicer, the Trust, the Trustee, the
Delaware Trustee and the Certificateholders thereto shall be fully protected against the claims of any creditors of the applicable
Servicer and of any creditors or depositors of the institution in which such account is maintained, (b) within FDIC insured
accounts (or other accounts with comparable insurance coverage acceptable to the Rating Agencies) created, maintained and monitored
by a Servicer or (c) in a separate non-trust account without FDIC or other insurance in an Eligible Institution (including the
Trustee). In the event that a Custodial Account for Reserves is established pursuant to clause (b) of the preceding sentence,
amounts held in such Custodial Account for Reserves shall not exceed the level of deposit insurance coverage on such account;
accordingly, more than one Custodial Account for Reserves may be established. Any amount that is at any time not protected or
insured in accordance with the first sentence of this definition of “Custodial Account for Reserves” shall promptly be
withdrawn from such Custodial Account for Reserves and be remitted to the Investment Account.


Custodial Agreement:  The agreement, if any, between the Trustee and a Custodian (or the Trustee, a Custodian and the Master
Servicer) providing for the safekeeping of the Mortgage Files on behalf of the Trust.


Custodian:  A custodian which is appointed by the Trustee with the consent of the Master Servicer, as provided in Article II
hereof, pursuant to a Custodial Agreement. Any Custodian so appointed shall act as agent on behalf of the Trustee.  The
reasonable fees and expenses of the Custodian shall be paid by the Master Servicer.  The Trustee shall remain at all times
responsible under the terms of this Agreement, notwithstanding the fact that certain duties have been assigned to a
Custodian.


Cut-Off Date:  January 1, 2005.


Definitive Certificates:  Certificates in definitive, fully registered and certificated form.


Delaware Trustee:  Deutsche Bank Trust Company Delaware, or its successor-in-interest as provided in Section 8.09, or any
successor trustee appointed as herein provided.


Depositary Agreement:  The Letter of Representations, dated January 14, 2005, by and among DTC, the Trust and the
Trustee.  The Trustee is authorized to enter into the Depositary Agreement on behalf of the Trust. 


Destroyed Mortgage Note:  A Mortgage Note the original of which (or a portion of the original of which) was permanently lost or
destroyed and has not been replaced.


Determination Date:  A day not later than the 10th day preceding a related Distribution Date, as determined by the Master
Servicer.


Disqualified Organization:  Any Person which is not a Permitted Transferee, but does not include any Pass-Through Entity which owns
or holds a Residual Certificate and of which a Disqualified Organization, directly or indirectly, may be a stockholder, partner or
beneficiary.


Distribution Date:  With respect to distributions on the REMIC I and REMIC II Regular Interests and the Certificates, the 25th
day (or, if such 25th day is not a Business Day, the Business Day immediately succeeding such 25th day) of each month, with the
first such date being February 25, 2005.  The “related Due Date” for any Distribution Date is the Due Date
immediately preceding such Distribution Date.


DTC:  The Depository Trust Company.


DTC Participant:  A broker, dealer, bank, other financial institution or other Person for whom DTC effects book-entry transfers and
pledges of securities deposited with DTC.


Due Date:  The day on which the Monthly Payment for each Mortgage Loan is due.


Eligible Institution:  An institution having (i) the highest short-term debt rating, and one of the two highest long-term debt
ratings of the Rating Agencies, (ii) with respect to any Custodial Account for P&I and special Custodial Account for Reserves,
an unsecured long-term debt rating of at least one of the two highest unsecured long-term debt ratings of the Rating Agencies,
(iii) with respect to any Buydown Fund Account or Custodial Account which also serves as a Buydown Fund Account, the highest
unsecured long-term debt rating by the Rating Agencies, or (iv) the approval of the Rating Agencies.  Such institution may be
the Servicer if the applicable Selling and Servicing Contract requires the Servicer to provide the Master Servicer with written
notice on the Business Day following the date on which the Servicer determines that such Servicer’s short-term debt and
unsecured long-term debt ratings fail to meet the requirements of the prior sentence.  Notwithstanding the foregoing,
Washington Mutual Bank, FA shall be an “Eligible Institution” if the following conditions are satisfied: (i) Washington
Mutual Bank, FA is acting as Servicer, (ii) if S&P is a Rating Agency as defined herein, the long-term unsecured debt
obligations of Washington Mutual Bank, FA are rated no lower than “A-” by S&P and the short-term unsecured debt
obligations of Washington Mutual Bank, FA are rated no lower than “A-2” by S&P, (iii) if Fitch is a Rating Agency
as defined herein, the long-term unsecured debt obligations of Washington Mutual Bank, FA are rated no lower than “A”
by Fitch and the short-term unsecured debt obligations of Washington Mutual Bank, FA are rated no lower than “F1” by
Fitch and (iv) if Moody’s is a Rating Agency as defined herein, the long-term unsecured debt obligations of Washington Mutual
Bank, FA are rated no lower than “A2” by Moody’s and the short-term unsecured debt obligations of Washington
Mutual Bank, FA are rated no lower than “P-1” by Moody’s; provided, that if the long-term or short-term unsecured
debt obligations of Washington Mutual Bank, FA are downgraded by any of the Rating Agencies to a rating lower than the applicable
rating specified in this sentence, Washington Mutual Bank, FA shall cease to be an “Eligible Institution” ten Business
Days after notification of such downgrade.


Eligible Investments:  Any one or more of the obligations or securities listed below in which funds deposited in the Investment
Account, the Certificate Account, the Custodial Account for P&I and the Custodial Account for Reserves may be
invested:


(i)                 
Obligations of, or guaranteed as to principal and interest by, the United States of America or any agency or instrumentality
thereof when such obligations are backed by the full faith and credit of the United States of America;


(ii)                Repurchase
agreements on obligations described in clause (i) of this definition of “Eligible Investments,” provided that the
unsecured obligations of the party (including the Trustee in its commercial capacity) agreeing to repurchase such obligations have
at the time one of the two highest short term debt ratings of the Rating Agencies and provided that such repurchaser’s
unsecured long term debt has one of the two highest unsecured long term debt ratings of the Rating Agencies;


(iii)               Federal funds,
certificates of deposit, time deposits and bankers’ acceptances of any U.S. bank or trust company incorporated under the laws
of the United States of America or any state (including the Trustee in its commercial capacity), provided that the debt obligations
of such bank or trust company (or, in the case of the principal bank in a bank holding company system, debt obligations of the bank
holding company) at the date of acquisition thereof have one of the two highest short term debt ratings of the Rating Agencies and
unsecured long term debt has one of the two highest unsecured long term debt ratings of the Rating Agencies;


(iv)              Obligations of, or
obligations guaranteed by, any state of the United States of America or the District of Columbia, provided that such obligations at
the date of acquisition thereof shall have the highest long-term debt ratings available for such securities from the Rating
Agencies;


(v)                Commercial paper
of any corporation incorporated under the laws of the United States of America or any state thereof, which on the date of
acquisition has the highest commercial paper rating of the Rating Agencies, provided that the corporation has unsecured long term
debt that has one of the two highest unsecured long term debt ratings of the Rating Agencies;


(vi)              Securities (other than
stripped bonds or stripped coupons) bearing interest or sold at a discount that are issued by any corporation incorporated under
the laws of the United States of America or any state thereof and have the highest long-term unsecured rating available for such
securities from the Rating Agencies; provided, however, that securities issued by any such corporation will not be
investments to the extent that investment therein would cause the outstanding principal amount of securities issued by such
corporation that are then held as part of the Investment Account or the Certificate Account to exceed 20% of the aggregate
principal amount of all Eligible Investments then held in the Investment Account and the Certificate Account; and


(vii)             Units of taxable money market funds
(which may be 12b-1 funds, as contemplated under the rules promulgated by the Securities and Exchange Commission under the
Investment Company Act of 1940), which funds have the highest rating available for such securities from the Rating Agencies or
which have been designated in writing by the Rating Agencies as Eligible Investments;


provided, however, that such obligation or security is held for a temporary period pursuant to Section 1.860G-2(g)(1) of the Treasury
Regulations, and that such period can in no event exceed thirteen months.


In no event shall an instrument be an Eligible Investment if such
instrument (a) evidences a right to receive only interest payments with respect to the obligations underlying such instrument or
(b) has been purchased at a price greater than the outstanding principal balance of such instrument.


ERISA:  The Employee Retirement Income Security Act of 1974, as amended.


ERISA Restricted Certificate:  Any Senior Subordinate Certificate.


Event of Default:  Any event of default as specified in Section 7.01.


Excess Liquidation Proceeds:  With respect to any Distribution Date, the sum of (i) the excess, if any, of aggregate
Liquidation Proceeds received during the Prior Period over the amount that would have been received if Payoffs had been made with
respect to such Mortgage Loans on the date such Liquidation Proceeds were received and (ii) any Excess Subsequent Recoveries for
such Distribution Date.


Excess Subsequent Recoveries: For any Distribution Date, the excess, if any, of (i) amounts received by the Master
Servicer during the Prior Period (after deduction of amounts reimbursable under Section 3.05(a)(i) and (ii)) in connection with the
liquidation of defaulted Mortgage Loans after such Mortgage Loans became Liquidated Mortgage Loans over (ii) the Subsequent
Recoveries for such Distribution Date.


Fannie Mae:  The entity formerly known as the Federal National Mortgage Association, or any successor thereto.


FDIC:  Federal Deposit Insurance Corporation, or any successor thereto.


FHA:  Federal Housing Administration, or any successor thereto.


Final Maturity Date:  With respect to each Class of the REMIC I and REMIC II Regular Interests and the Residual Interests,
the date set forth in the applicable table contained in the Preliminary Statement hereto.  With respect to each Class of Class
A, Class B and Class X Certificates, the date set forth for its Corresponding Class of REMIC II Regular Interests in the applicable
table contained in the Preliminary Statement hereto. 


Fitch: Fitch Ratings, provided that at any time it be a Rating
Agency.


Freddie Mac:  The entity formerly known as the Federal Home Loan Mortgage Corporation, or any successor thereto.


GCD:  Greenwich Capital Derivatives, Inc.


Index:  For each Mortgage Loan, One-Year MTA.  For each Mortgage Loan and each Interest Rate Adjustment Date, the One-Year
MTA figure used to calculate the Mortgage Interest Rate will be the most recent One-Year MTA figure available as of fifteen days
before such Interest Rate Adjustment Date.  In the event One-Year MTA (or a substitute index) is no longer available, the
Master Servicer will select a substitute index in accordance with the Mortgage Note.


Indirect DTC Participants:  Entities such as banks, brokers, dealers or trust companies, that clear through or maintain a custodial
relationship with a DTC Participant, either directly or indirectly.


Initial Custodial Agreement:  The Custodial Agreement, dated the date hereof, among the Trustee, the Master Servicer and the
Initial Custodian.


Initial Custodian:  Washington Mutual Bank fsb, which has been designated by the Company to be appointed by the Trustee to act
as Custodian, and whose appointment has been approved by the Master Servicer.


Insurance Proceeds:  Amounts paid or payable by the insurer under any Primary Insurance Policy or any other insurance policy
(including any replacement policy permitted under this Agreement) covering any Mortgage Loan or Mortgaged Property, including,
without limitation, any hazard insurance policy required pursuant to Section 3.07, any title insurance policy required pursuant to
Section 2.08 and any FHA insurance policy or VA guaranty.


Interest Distribution Amount:  For any Distribution Date for any Class of REMIC I Regular Interests, REMIC II Regular Interests
and the Class R-1 Residual Interest, the amount of interest accrued during the Prior Period (or in the case of the Class A-L and
Class B-L Regular Interests, during the No-Delay Accrual Period), at the related Certificate Interest Rate for such Class for such
Distribution Date, on the respective Class Principal Balance or Class Notional Amount, as applicable, immediately before such
Distribution Date, reduced by Net Negative Amortization Amounts, Uncompensated Interest Shortfall and the interest portion of
Realized Losses allocated to such Class on such Distribution Date pursuant to the definitions of “Net Negative Amortization
Amount,” “Uncompensated Interest Shortfall” and “Realized Loss,” respectively.


The computation of interest accrued on the Class A-L Regular Interests
shall be made on the basis of a ratio, the numerator of which is the actual number of days in the accrual period and the
denominator of which is 360.


The computation of interest accrued on the Class X-L and Class
B-L Regular Interests and Residual Interests shall be made on the basis of a 360-day year of twelve 30-day months. The interest
accrual period for the Class X-L or Class B-L Regular Interests or Residual Interests shall be deemed to consist of 30
days.


Interest Rate Adjustment Date:  As to each Mortgage Loan, the initial Due Date on which an
adjustment to the Mortgage Interest Rate of such Mortgage Loan becomes effective.


Investment Account:  The commingled account (which shall be commingled only with investment accounts related to series of
pass-through certificates with a class of certificates which has a rating equal to the highest of the Ratings of the Certificates)
maintained by the Master Servicer in the trust department of the Investment Depository pursuant to Section 3.03 and which bears a
designation acceptable to the Rating Agencies.


Investment Depository:  JPMorgan Chase Bank, N.A. or another bank or trust company designated from time to time by the Master
Servicer. The Investment Depository shall at all times be an Eligible Institution.


Junior Subordinate Certificates:  The Class B-4, Class B-5 and Class B-6 Certificates.


Last Scheduled Distribution Date:  With respect to any Class of Certificates, the Final Maturity Date for such
Class.


Lender:  An institution from which the Company purchased any Mortgage Loans pursuant to a Selling and Servicing
Contract.


LIBOR: The London Interbank Offered Rate for one-month United States dollar deposits calculated in the
manner described in Section 3.19.


LIBOR Determination Date: With respect to interest paid on any Distribution Date, the second day on which banks in London
and New York City are open for conducting transactions in foreign currency and exchange prior to the 25th day of the month
preceding the Distribution Date.


Liquidated Mortgage Loan:  A Mortgage Loan (other than a Mortgage Loan with respect to which a Payoff has been made) for which the
Master Servicer or the applicable Servicer has determined in accordance with its customary servicing practices that it has received
all amounts which it expects to recover from or on account of such Mortgage Loan, whether from Insurance Proceeds, Liquidation
Proceeds or otherwise. For purposes of this definition, acquisition of a Mortgaged Property by the Trust shall not constitute final
liquidation of the related Mortgage Loan.


Liquidation Principal:  The principal portion of Liquidation Proceeds received with respect to each Mortgage Loan which became a
Liquidated Mortgage Loan (but not in excess of the principal balance thereof) during the Prior Period.


Liquidation Proceeds:  Amounts after deduction of amounts reimbursable under Section 3.05(a)(i) and (ii) received and retained in
connection with the liquidation of defaulted Mortgage Loans, whether through foreclosure or otherwise, other than any Subsequent
Recoveries.


Loan-to-Value Ratio:  The original principal amount of a Mortgage Loan divided by the Original Value; provided, however,
that references to “current Loan-to-Value Ratio” or “Loan-to-Value Ratio as of the Cut-Off Date” in Section
2.08 shall be deemed to mean the then current Principal Balance of a Mortgage Loan divided by the Original Value.


Lowest Class B Owner:  An owner unaffiliated with the Company or the Master Servicer of (i) a 100% interest in the Class of Class
B Certificates with the lowest priority or (ii) a 100% interest in a class of securities representing such interest in such Class
specified in clause (i) above.


Marker Rate:  With respect to the Class X Certificates and any Distribution Date, in relation to the REMIC I Regular
Interests LT1, LT2, LT3 and LT4, a per annum rate equal to two (2) times the weighted average of the Certificate Interest Rates for
REMIC I Regular Interest LT2 and REMIC I Regular Interest LT3.


Master Servicer:  The Company, or any successor thereto appointed as provided pursuant to Section 7.02, acting to service and
administer the Mortgage Loans pursuant to Section 3.01.


Master Servicer Business Day:  Any day other than a Saturday, a Sunday, or a day on which banking institutions in Chicago,
Illinois are authorized or obligated by law or executive order to be closed.


Master Servicing Fee:  For each Mortgage Loan, the fee charged by the Master Servicer for supervising the mortgage servicing and
advancing certain expenses, equal to 1/12 of the product of (i) the Master Servicing Fee Rate for such Mortgage Loan and (ii) the
outstanding Principal Balance of such Mortgage Loan, payable monthly from the Certificate Account, the Investment Account or the
Custodial Account for P&I.


Master Servicing Fee Rate:  For each Mortgage Loan, the per annum rate set forth for such Mortgage Loan in the Mortgage Loan
Schedule, equal to 0.050%.


MERS:  Mortgage Electronic Registration Systems, Inc., a Delaware corporation, or any successor thereto.


MERS Loan:  Any Mortgage Loan registered on the MERS® System for which MERS appears as the mortgagee of record on the Mortgage
or on an assignment thereof.


MERS® System:  The system of electronically recording transfers of Mortgages maintained by MERS.


MIN:  The Mortgage Identification Number for a MERS Loan.


Minimum Monthly Payment:  For each Mortgage Loan, the minimum Monthly Payment required to be paid by the Mortgagor pursuant to
the terms of the related Mortgage Note.


MOM Loan:  A Mortgage Loan that was registered on the MERS® System at the time of origination thereof and for which MERS
appears as the mortgagee of record on the Mortgage.


Monthly P&I Advance:  An advance of funds by the Master Servicer pursuant to Section 4.02 or a Servicer pursuant to its
Selling and Servicing Contract to cover delinquent principal and interest installments.


Monthly Payment:  The payment of principal and interest on a Mortgage Loan (which payment may be less than the amount of interest
accrued on such Mortgage Loan due to the related Monthly Payment Adjustment Terms) (including any amounts due from a Buydown Fund,
if any) which is received on the related Due Date for such Mortgage Loan.


Monthly Payment Adjustment Terms:  As to each Mortgage Loan, the terms for adjusting the amount of
the Minimum Monthly Payment on such Mortgage Loan, as set forth in the related Mortgage Note, including the dates on which or the
circumstances under which such adjustments become effective and limitations on the amounts of such adjustments.


Moody’s:  Moody’s Investors Service, Inc., provided that at any time it be a Rating Agency.


Mortgage:  The mortgage, deed of trust or other instrument securing a Mortgage Note.


Mortgage File:  The following documents or instruments with respect to each Mortgage Loan transferred and assigned by the Company
pursuant to Section 2.04, (X) with respect to each Mortgage Loan that is not a Cooperative Loan:


(i)         The original Mortgage Note endorsed (A) in blank, without recourse, or
(B) to “Deutsche Bank National Trust Company, as Trustee, without recourse” or to “WaMu Mortgage Pass-Through
Certificates Series 2005-AR1 Trust, without recourse” and all intervening endorsements evidencing a complete chain of
endorsements from the originator to the Trustee or the Trust, as applicable, or, in the event of any Destroyed Mortgage Note, a
copy or a duplicate original of the Mortgage Note, together with an original lost note affidavit from the originator of the
Mortgage Loan or the Company (or any affiliate of the Company from which the Company acquired the Mortgage Loan), as applicable,
stating that the original Mortgage Note (or portion thereof, as applicable) was lost, misplaced or destroyed, together with a copy
of the Mortgage Note; provided, however, that in the event the Company acquired the Mortgage Loan from an affiliate of the
Company, then the Mortgage Note need not be endorsed in blank or to Deutsche Bank National Trust Company or the Trust as provided
above (but, if not so endorsed, shall be made payable to, or endorsed by the mortgagee named therein to, such affiliate of the
Company);


(ii)        The Buydown Agreement, if applicable;


(iii)       A Mortgage that is either


(1)        (x) the original recorded Mortgage with evidence of recording thereon for the
jurisdiction in which the Mortgaged Property is located (which original recorded Mortgage, in the case of a MOM Loan, shall set
forth the MIN and shall indicate that the Mortgage Loan is a MOM Loan), (y) unless the Mortgage Loan is a MERS Loan, an original
Mortgage assignment thereof duly executed and acknowledged in recordable form (A) in blank or (B) to “Deutsche Bank National
Trust Company, as Trustee,” or to “WaMu Mortgage Pass-Through Certificates Series 2005-AR1 Trust,” and (z) unless
the Mortgage Loan is a MOM Loan, recorded originals of all intervening assignments evidencing a complete chain of assignment, from
the originator to the name holder or the payee endorsing the related Mortgage Note (or, in the case of a MERS Loan other than a MOM
Loan, from the originator to MERS); or


(2)        (x) a copy (which may be in electronic form) of the Mortgage (which Mortgage,
in the case of a MOM Loan, shall set forth the MIN and shall indicate that the Mortgage Loan is a MOM Loan) which represents a true
and correct reproduction of the original Mortgage and which has either been certified (i) on the face thereof by the public
recording office in the appropriate jurisdiction in which the Mortgaged Property is located, or (ii) by the originator, the related
Lender or the escrow or title company which provided closing services in connection with such Mortgage Loan as a true and correct
copy the original of which has been sent for recordation, (y) unless the Mortgage Loan is a MERS Loan, an original Mortgage
assignment thereof duly executed and acknowledged in recordable form (A) in blank or (B) to “Deutsche Bank National Trust
Company, as Trustee,” or to “WaMu Mortgage Pass-Through Certificates Series 2005-AR1 Trust” and (z) unless the
Mortgage Loan is a MOM Loan, true and correct copies, certified by the applicable county recorder or by the originator or Lender as
described above, of all intervening assignments evidencing a complete chain of assignment from the originator to the name holder or
the payee endorsing the related Mortgage Note (or, in the case of a MERS Loan other than a MOM Loan, from the originator to
MERS);


provided, however, that in the event the Company
acquired the Mortgage Loan from an affiliate of the Company, then the Mortgage File need not include a Mortgage assignment executed
in blank or to Deutsche Bank National Trust Company or the Trust as provided in clause (X)(iii)(1)(y) or (X)(iii)(2)(y) above, as
applicable (but the Mortgage File shall, unless the Mortgage Loan was originated by such affiliate of the Company, include an
intervening Mortgage assignment to such affiliate as provided in clause (X)(iii)(1)(z) or (X)(iii)(2)(z) above, as applicable);
and


(iv)       For any Mortgage Loan that has been modified or amended, the original instrument or
instruments effecting such modification or amendment;


and (Y) with respect to each Cooperative Loan:


(i)         The original Mortgage Note endorsed (A) in blank, without recourse, or
(B) to “Deutsche Bank National Trust Company, as Trustee, without recourse” or to “WaMu Mortgage Pass-Through
Certificates Series 2005-AR1 Trust, without recourse” and all intervening endorsements evidencing a complete chain of
endorsements, from the originator to the Trustee or the Trust, as applicable, or, in the event of any Destroyed Mortgage Note, a
copy or a duplicate original of the Mortgage Note, together with an original lost note affidavit from the originator of the
Cooperative Loan or the Company (or any affiliate of the Company from which the Company acquired the Mortgage Loan), as applicable,
stating that the original Mortgage Note (or portion thereof, as applicable) was lost, misplaced or destroyed, together with a copy
of the Mortgage Note; provided, however, that in the event the Company acquired the Cooperative Loan from an affiliate of
the Company, then the Mortgage Note need not be endorsed in blank or to Deutsche Bank National Trust Company or the Trust as
provided above (but, if not so endorsed, shall be made payable to, or endorsed by the originator or successor lender named therein
to, such affiliate of the Company);


(ii)        A counterpart of the Cooperative Lease and the Assignment of Proprietary
Lease to the originator of the Cooperative Loan;


(iii)       The related Cooperative Stock Certificate, representing the related Cooperative
Stock pledged with respect to such Cooperative Loan, together with an undated stock power (or other similar instrument) executed in
blank;


(iv)       The Recognition Agreement;


(v)        The Security Agreement;


(vi)       Copies of the original UCC financing statement, and any continuation statements,
filed by the originator of such Cooperative Loan as secured party, each with evidence of recording thereof, evidencing the interest
of the originator under the Security Agreement and the Assignment of Proprietary Lease;


(vii)      Copies of the filed UCC assignments or amendments of the security interest referenced in
clause (vi) above showing an unbroken chain of title from the originator to the Trust, each with evidence of recording thereof,
evidencing the interest of the assignee under the Security Agreement and the Assignment of Proprietary Lease;


(viii)      An executed assignment of the interest of the originator in the Security Agreement, the
Assignment of Proprietary Lease and the Recognition Agreement, showing an unbroken chain of title from the originator to the Trust;
and


(ix)       For any Cooperative Loan that has been modified or amended, the original instrument
or instruments effecting such modification or amendment;


provided,
however, that in the event the Company acquired the Cooperative Loan from an
affiliate of the Company, then the Mortgage File need not include (1) a UCC assignment or amendment of the security interest
referenced in clause (Y)(vi) above to the Trust as provided in clause (Y)(vii) above (but the Mortgage File shall, unless the
Cooperative Loan was originated by such affiliate of the Company, include a UCC assignment or amendment of such security interest
to such affiliate) or (2) an assignment of the interest of the originator in the Security Agreement, the Assignment of Proprietary
Lease and the Recognition Agreement to the Trust as provided in clause (Y)(viii) above (but the Mortgage File shall, unless the
Cooperative Loan was originated by such affiliate of the Company, include an assignment of such interest to such
affiliate).


Mortgage Interest Rate:  For any Mortgage Loan, the per annum rate at which interest accrues on such Mortgage Loan pursuant to the
terms of the related Mortgage Note.


Mortgage Loan Margin:  For each Mortgage Loan, the applicable fixed per annum percentage rate specified in the applicable Mortgage
Note and designated as such in the Mortgage Loan Schedule; provided, however, that in the event the Index is replaced, the
Mortgage Loan Margin will be increased or decreased pursuant to the related Mortgage Note.


Mortgage Loan Schedule:  The schedule, as amended from time to time, of Mortgage Loans attached hereto as Exhibit D, which shall set
forth as to each Mortgage Loan the following, among other things:


(i)         its loan number,


(ii)        the address of the Mortgaged Property,


(iii)       the name of the Mortgagor,


(iv)       the Original Value of the property subject to the Mortgage,


(v)        the Principal Balance as of the Cut-Off Date,


(vi)       the Mortgage Interest Rate, as of the Cut-Off Date, borne by the Mortgage Note and
the Rate Ceiling and Mortgage Loan Margin borne by the Mortgage Note, and the Index, Interest Rate Adjustment Date and Monthly
Payment Adjustment Terms applicable to such Mortgage Loan,


(vii)      whether a Primary Insurance Policy is in effect as of the Cut-Off Date, and, if so,
whether such Primary Insurance Policy is a Special Primary Insurance Policy,


(viii)      the maturity of the Mortgage Note,


(ix)       the Master Servicing Fee Rate and the Servicing Fee Rate, and


(x)       
whether it imposes penalties for early prepayments.


Mortgage Loans:  The mortgage loans and cooperative loans (if any) listed on the Mortgage Loan Schedule and transferred and
assigned to the Trust pursuant hereto. With respect to each Mortgage Loan that is a Cooperative Loan, “Mortgage Loan”
shall include, but not be limited to, the Mortgage Note, Security Agreement, Assignment of Proprietary Lease, Recognition
Agreement, Cooperative Stock Certificate and Cooperative Lease, and, with respect to each Mortgage Loan other than a Cooperative
Loan, “Mortgage Loan” shall include, but not be limited to the Mortgage Note and the related Mortgage.


Mortgage Note:  The note or other evidence of the indebtedness of a Mortgagor under a Mortgage Loan.


Mortgage Pool:  All of the Mortgage Loans.


Mortgage Pool Assets:  (i) The Mortgage Loans (including all Substitute Mortgage Loans) identified on the Mortgage Loan Schedule,
and all rights pertaining thereto, including the related Mortgage Notes, Mortgages, Cooperative Stock Certificates, Cooperative
Leases, Security Agreements, Assignments of Proprietary Lease, and Recognition Agreements, and all payments and distributions with
respect to the Mortgage Loans payable on and after the Cut-Off Date; (ii) the Certificate Account, the Investment Account, and
all money, instruments, investment property, and other property credited thereto, carried therein, or deposited therein (except
amounts constituting the Master Servicing Fee or the Servicing Fee); (iii) the Custodial Accounts for P&I, the Custodial
Accounts for Reserves, any Buydown Fund Account (to the extent of the amounts on deposit or other property therein attributable to
the Mortgage Loans), and all money, instruments, investment property, and other property credited thereto, carried therein, or
deposited therein (except amounts constituting the Master Servicing Fee or the Servicing Fee); (iv) all property that secured a
Mortgage Loan and that has been acquired by foreclosure or deed in lieu of foreclosure or, in the case of a Cooperative Loan, a
similar form of conversion, after the Cut-Off Date; and (v) each FHA insurance policy, Primary Insurance Policy, VA guaranty, and
other insurance policy related to any Mortgage Loan, and all amounts paid or payable thereunder and all proceeds
thereof.


Mortgaged Property:  With respect to any Mortgage Loan, other than a Cooperative Loan, the real property, together with
improvements thereto, and, with respect to any Cooperative Loan, the related Cooperative Stock and Cooperative Lease, securing the
indebtedness of the Mortgagor under the related Mortgage Loan.  “Mortgaged Property” shall also refer to property
which once secured the indebtedness of a Mortgagor under the related Mortgage Loan but which was acquired by the Trust upon
foreclosure or other liquidation of such Mortgage Loan.


Mortgagor:  The obligor on a Mortgage Note.


Negative Amortization Amount: For any Due Date for any Mortgage Loan, the excess, if any, of (i) the amount of interest accrued on
such Mortgage Loan, during the monthly period immediately preceding such Due Date, at the related Mortgage Interest Rate, over (ii)
the greater of (a) the Monthly Payment received on such Mortgage Loan on such Due Date and (b) the Minimum Monthly Payment due on
such Mortgage Loan on such Due Date.


Net Negative Amortization Amount: For any Distribution Date, the excess, if any, of (i) the aggregate of Negative Amortization Amounts
with respect to the Mortgage Loans for the Due Date in the calendar month of such Distribution Date over (ii) the sum of
(a) Curtailments received during the Prior Period from the Mortgage Loans and (b) Payoffs received during the Payoff
Period from the Mortgage Loans.


For any Distribution Date, (a) the Net Negative Amortization Amount
for such Distribution Date shall be allocated to the Class LT-1 Regular Interest, in reduction of the Interest Distribution Amount
for such Class, and (b) the Class LT-1 Principal Balance shall be increased by the Net Negative Amortization Amount for such
Distribution Date.


For any Distribution Date, (a) the Net Negative Amortization Amount
for such Distribution Date shall be allocated among the REMIC II Regular Interests in proportion to the excess, if any, for each
such Class of (i) the amount of interest accrued during the Prior Period (or in the case of the Class A-L and Class B-L Regular
Interests, during the No-Delay Accrual Period) on the Class Principal Balance or Class Notional Amount, as applicable, for such
Class at the applicable Certificate Interest Rate for such Class, over (ii) the amount of interest that would have accrued during
the Prior Period (or in the case of the Class A-L and Class B-L Regular Interests, during the No-Delay Accrual Period) on the Class
Principal Balance or Class Notional Amount, as applicable, for such Class had the Certificate Interest Rate for such Class equaled
the related Adjusted Cap Rate for such Class and for such Distribution Date, in reduction of the Interest Distribution Amount for
each such Class, and (b) the Class Principal Balance for each Class of REMIC II Regular Interests shall be increased by the amount
allocated to such Class in reduction of the Interest Distribution Amount thereof pursuant to clause (a) of this
sentence.


No-Delay Accrual Period:  For any Distribution Date, the period beginning on the 25th day of the month preceding that
Distribution Date and ending on the 24th day of the month of that Distribution Date.


Nonrecoverable Advance:  With respect to any Mortgage Loan, any advance which the Master Servicer shall determine to be a
Nonrecoverable Advance pursuant to Section 4.03 and which was, or is proposed to be, made by (i) the Master Servicer or (ii) a
Servicer pursuant to its Selling and Servicing Contract.


Non-U.S. Person:  A Person that is not a U.S. Person.


Notice Addresses:  (a) In the case of the Company, 75 North Fairway Drive, Vernon Hills, Illinois 60061, Attention: Master
Servicing Department (with a copy to: Washington Mutual Legal Department, 1201 Third Avenue, WMT 1706, Seattle, WA 98101,
Attention: WMMSC) or such other address as may hereafter be furnished to the Trustee in writing by the Company, (b) in the case of
the Trustee, at its Corporate Trust Office, or such other address as may hereafter be furnished to the Master Servicer in writing
by the Trustee, (c) in the case of the Delaware Trustee, 1011 Centre Road, Suite 200, Wilmington, Delaware 19805-1266, or such
other address as may hereafter be furnished to the Master Servicer in writing by the Delaware Trustee, (d) in the case of the
Trust, c/o Deutsche Bank National Trust Company, at the Corporate Trust Office, or such other address as may hereafter be furnished
to the Master Servicer in writing by the Trustee, (e) in the case of the Certificate Registrar, at its Corporate Trust Office, or
such other address as may hereafter be furnished to the Trustee in writing by the Certificate Registrar, (f) in the case of
S&P, 55 Water Street, 41st Floor, New York, New York 10041-0003, Attention:  Frank Raiter, or such other address as may
hereafter be furnished to the Trustee and Master Servicer in writing by S&P and (g) in the case of Moody’s, 99 Church
Street, New York, New York 10007, Attention:  Monitoring, or such other address as may hereafter be furnished to the Trustee
and Master Servicer in writing by Moody’s.


Novation Agreement:  The Novation Agreement, dated as of January 18, 2005, among GCD, Washington Mutual Bank, FA and the
Trustee.


OTS:  The Office of Thrift Supervision, or any successor thereto.


Officer’s Certificate:  A certificate signed by the Chairman of the Board, the President, a Vice President, or the
Treasurer of the Master Servicer and delivered to the Trustee or the Delaware Trustee, as applicable.


One-Year MTA:  The twelve-month moving average monthly yield on United States Treasury Securities adjusted to a constant maturity
of one year as published by the Federal Reserve Board in the Federal Reserve Statistical Release “Selected Interest Rates
(H.15),” determined by averaging the monthly yields for the most recently available twelve months.


Opinion of Counsel:  A written opinion of counsel, who shall be reasonably acceptable to the Trustee or the Delaware Trustee, as
applicable, and who may be counsel (including in-house counsel) for the Company or the Master Servicer.


Original Trust Agreement:  The Trust Agreement, dated as of January 1, 2005, between the Company and the Delaware Trustee,
providing for the creation of the Trust.


Original Value:  With respect to any Mortgage Loan other than a Mortgage Loan originated for the purpose of refinancing an existing
mortgage debt, the lesser of (a) the Appraised Value (if any) of the Mortgaged Property at the time the Mortgage Loan was
originated or (b) the purchase price paid for the Mortgaged Property by the Mortgagor.  With respect to a Mortgage Loan
originated for the purpose of refinancing existing mortgage debt, the Original Value shall be equal to the Appraised Value of the
Mortgaged Property.


Ownership Interest:  With respect to any Residual Certificate, any ownership or security interest in such Residual Certificate,
including any interest in a Residual Certificate as the Holder thereof and any other interest therein whether direct or indirect,
legal or beneficial, as owner or as pledgee.


Pass-Through Entity:  Any regulated investment company, real estate investment trust, common trust fund, partnership, trust or
estate, and any organization to which Section 1381 of the Code applies.


Pass-Through Rate:  For each Mortgage Loan, the Mortgage Interest Rate for such Mortgage Loan less (i) the Servicing Fee Rate
for such Mortgage Loan, (ii) the Master Servicing Fee Rate for such Mortgage Loan and (iii) if such Mortgage Loan was covered by a
Special Primary Insurance Policy on the Closing Date (even if no longer so covered), the per annum rate at which the applicable
Special Primary Insurance Premium for such Mortgage Loan is calculated. For each Mortgage Loan, any calculation of monthly interest
at such rate shall be based upon annual interest at such rate (computed on the basis of a 360-day year of twelve 30-day months) on
the unpaid Principal Balance of such Mortgage Loan divided by twelve, and any calculation of interest at such rate by reason of a
Payoff shall be based upon annual interest at such rate on the outstanding Principal Balance of such Mortgage Loan multiplied by a
fraction, the numerator of which is the number of days elapsed from the Due Date of the last scheduled payment of principal and
interest to, but not including, the date of such Payoff, and the denominator of which is (a) for Payoffs received on a Due Date,
360, and (b) for all other Payoffs, 365.


Paying Agent:  Any paying agent appointed by the Trustee pursuant to Section 8.12.


Payoff:  Any Mortgagor payment of principal on a Mortgage Loan equal to the entire outstanding Principal Balance of such
Mortgage Loan, if received in advance of the last scheduled Due Date for such Mortgage Loan and accompanied by an amount of
interest equal to accrued unpaid interest on the Mortgage Loan to the date of such payment-in-full.  (Prepayment penalties are
not payments of principal and hence Payoffs do not include prepayment penalties.)


Payoff Earnings:  For any Distribution Date with respect to each Mortgage Loan on which a Payoff was received by the Master Servicer
during the Payoff Period, the aggregate of the interest earned by the Master Servicer from investment of each such Payoff from the
date of receipt of such Payoff until the Business Day immediately preceding the related Distribution Date (net of investment
losses).


Payoff Interest:  For any Distribution Date with respect to a Mortgage Loan for which a Payoff was received on or after the first
calendar day of the month of such Distribution Date and before the 15th calendar day of such month, an amount of interest thereon
at the applicable Pass-Through Rate from the first day of the month of distribution through the day of receipt thereof; to the
extent (together with Payoff Earnings and the aggregate Master Servicing Fee) not required to be distributed as Compensating
Interest on such Distribution Date, Payoff Interest shall be payable to the Master Servicer as additional servicing
compensation.


Payoff Period:  For the first Distribution Date, the period from the Cut-Off Date through February 14, 2005, inclusive; and
for any Distribution Date thereafter, the period from the 15th day of the Prior Period through the 14th day of the month of such
Distribution Date, inclusive.


Percentage Interest:  (a)  With respect to the right of each Certificate of a particular Class in the distributions
allocated to such Class, “Percentage Interest” shall mean the percentage equal to:


(i)         with respect to any Certificate (other than the Class X and Residual
Certificates), its Certificate Principal Balance divided by the applicable Class Principal Balance;


(ii)        with respect to any Class X Certificate, the portion of the Class X-L
Notional Amount evidenced by such Certificate divided by the Class X-L Notional Amount; and


(iii)       with respect to any Residual Certificate, the percentage set forth on the face of
such Certificate.


(b)        With respect to the
rights of each Certificate in connection with Sections 5.09, 7.01, 8.01(c), 8.02, 8.07, 10.01 and 10.03, “Percentage
Interest” shall mean the percentage equal to:


(i)         with respect to any Certificate (other than the Class X and Residual
Certificates), the product of (x) ninety-nine percent (99%) and (y) its Certificate Principal Balance divided by the Aggregate
Certificate Principal Balance of the Certificates; provided, however, that the percentage in clause (x) above shall be
increased by one percent (1%) upon the retirement of the Class X Certificates;


(ii)        with respect to any Class X Certificate, one percent (1%) of such
Certificate’s Percentage Interest as calculated by paragraph (a)(ii) of this definition; and


(iii)       with respect to any Residual Certificate, zero.


Permitted Transferee:  With respect to the holding or ownership of any Residual Certificate, any Person other than (i) the United
States, a State or any political subdivision thereof, or any agency or instrumentality of any of the foregoing, (ii) a foreign
government, International Organization or any agency or instrumentality of either of the foregoing, (iii) an organization (except
certain farmers’ cooperatives described in Code Section 521) which is exempt from the taxes imposed by Chapter 1 of the
Code (unless such organization is subject to the tax imposed by Section 511 of the Code on unrelated business taxable income), (iv)
rural electric and telephone cooperatives described in Code Section 1381(a)(2)(C), (v) any “electing large partnership”
as defined in Section 775(a) of the Code, (vi) any Person from whom the Trustee has not received an affidavit to the effect that it
is not a “disqualified organization” within the meaning of Section 860E(e)(5) of the Code, and (vii) any other Person
so designated by the Company based upon an Opinion of Counsel that the transfer of an Ownership Interest in a Residual Certificate
to such Person may cause REMIC I or REMIC II to fail to qualify as a REMIC at any time that the Certificates are outstanding. The
terms “United States,” “State” and “International Organization” shall have the meanings set
forth in Code Section 7701 or successor provisions. A corporation shall not be treated as an instrumentality of the United States
or of any State or political subdivision thereof if all of its activities are subject to tax, and, with the exception of the
Freddie Mac, a majority of its board of directors is not selected by such governmental unit.


Person:  Any individual, corporation, limited liability company, partnership, joint venture, association, joint-stock company,
trust, unincorporated organization or government or any agency or political subdivision thereof.


Prepaid Monthly Payment:  Any Monthly Payment received prior to its scheduled Due Date, which is intended to be applied to a
Mortgage Loan on its scheduled Due Date and held in the related Custodial Account for P&I until the Withdrawal Date following
its scheduled Due Date.


Primary Insurance Policy:  A policy of mortgage guaranty insurance, if any, on an individual Mortgage Loan or on pools of mortgage
loans that include an individual Mortgage Loan, providing coverage as required by Section 2.08(xi) (including any Special Primary
Insurance Policy).


Principal Balance:  Except as used in Sections 2.07, 3.09 and 9.01 and for purposes of the definition of Purchase Price, at the
time of any determination, the principal balance of a Mortgage Loan remaining to be paid at the close of business on the
Cut‐Off Date, after application of all scheduled principal payments due on or before the Cut‐Off Date, whether or not
received, reduced by all amounts distributed or (except when such determination occurs earlier in the month than the Distribution
Date) to be distributed to Certificateholders through the Distribution Date in the month of determination that are reported as
allocable to principal of such Mortgage Loan, and increased by all Negative Amortization Amounts for such Mortgage Loan for prior
Due Dates.


For purposes of the definition of Purchase Price and as used in
Sections 2.07, 3.09 and 9.01, at the time of any determination, the principal balance of a Mortgage Loan remaining to be paid at
the close of business on the Cut-Off Date, after deduction of all scheduled principal payments due on or before the Cut-Off Date,
whether or not received, reduced by all amounts distributed or to be distributed to Certificateholders through the Distribution
Date in the month of determination that are reported as allocable to principal of such Mortgage Loan, and increased by all Negative
Amortization Amounts for such Mortgage Loan for prior Due Dates.


In the case of a Substitute Mortgage Loan, “Principal
Balance” shall mean, at the time of any determination, the principal balance of such Substitute Mortgage Loan transferred to
the Trust, on the date of substitution, reduced by all amounts distributed or to be distributed to Certificateholders through the
Distribution Date in the month of determination that are reported as allocable to principal of such Substitute Mortgage Loan, and
increased by all Negative Amortization Amounts for such Substitute Mortgage Loan for prior Due Dates since the date of
substitution.


The Principal Balance of a Mortgage Loan (including a Substitute
Mortgage Loan) shall not be adjusted solely by reason of any bankruptcy or similar proceeding or any moratorium or similar waiver
or grace period. Whenever a Realized Loss has been incurred with respect to a Mortgage Loan during a calendar month, the Principal
Balance of such Mortgage Loan shall be reduced by the amount of such Realized Loss as of the Due Date next following the end of
such calendar month. The Principal Balance of each Mortgage Loan shall be increased, as of each Due Date, by the amount of any
Negative Amortization Amount for such Mortgage Loan for such Due Date.


Principal Payment:  Any payment of principal on a Mortgage Loan other than a Principal Prepayment.


Principal Payment Amount:  For any Distribution Date, the sum of (i) the scheduled principal payments (if any) on the Mortgage
Loans due on the related Due Date, (ii) the principal portion of proceeds received with respect to any Mortgage Loan which was
purchased or repurchased pursuant to a Purchase Obligation or as permitted by this Agreement during the Prior Period and (iii) any
other unscheduled payments of principal which were received with respect to any Mortgage Loan during the Prior Period, other than
Payoffs, Curtailments, Liquidation Principal and Subsequent Recoveries.


Principal Prepayment:  Any payment of principal on a Mortgage Loan which constitutes a Payoff or a Curtailment.


Principal Prepayment Amount:  For any Distribution Date, the sum of (i) Curtailments received during the Prior Period from the
Mortgage Loans and (ii) Payoffs received during the Payoff Period from the Mortgage Loans, such sum reduced (but not to less than
zero) by the aggregate of Negative Amortization Amounts with respect to the Mortgage Loans for the Due Date in the calendar month
of such Distribution Date.


Prior Period:  With respect to any Distribution Date, the calendar month immediately preceding such Distribution Date.


Pro Rata Allocation:  The allocation of the principal portion of Realized Losses to all Classes of REMIC II Regular Interests pro
rata according to their respective Class Principal Balances in reduction thereof, and the allocation of the interest portion of
Realized Losses to all Classes of REMIC II Regular Interests pro rata according to the amount of interest accrued but unpaid on
each such Class, in reduction thereof, and then to such Classes pro rata according to their respective Class Principal Balances in
reduction thereof.


Prospectus:   The Prospectus, dated February 10, 2004, and the Prospectus Supplement, dated January 13, 2005, of the
Company.


Purchase Obligation:  An obligation of the Company to repurchase Mortgage Loans under the circumstances and in the manner
provided in Section 2.07 or Section 2.08.


Purchase Price:  With respect to any Mortgage Loan to be purchased pursuant to a Purchase Obligation or pursuant to Section 3.01,
an amount equal to the sum of (i) the Principal Balance thereof, (ii) unpaid accrued interest thereon, if any, during the calendar
month in which the date of purchase occurs to the last day of such month at a rate equal to the applicable Pass-Through Rate and
(iii) with respect to any Mortgage Loan to be purchased pursuant to Section 2.08, any costs and damages incurred by the Trust in
connection with any violation by such Mortgage Loan of any predatory and abusive lending laws, to the extent such costs and damages
result from a breach of the representation and warranty made by the Company pursuant to clause (viii) of Section 2.08; provided,
however, that to the extent that such costs and damages constitute a set-off against the principal balance of the Mortgage
Loan, such costs and damages will not be paid pursuant to this clause (iii), and the amount paid pursuant to clause (i) above will
be calculated without regard to such set-off; provided, further, that no Mortgage Loan shall be purchased or required to be
purchased pursuant to Section 2.08, or more than two years after the Closing Date under Section 2.07, unless (a) the Mortgage Loan
to be purchased is in default, or default is in the judgment of the Company reasonably imminent, or (b) the Company, at its
expense, delivers to the Trustee an Opinion of Counsel addressed to the Trust and the Trustee to the effect that the purchase of
such Mortgage Loan will not give rise to a tax on a prohibited transaction, as defined in Section 860F(a) of the Code.


Qualified Insurer:  A mortgage guaranty insurance company duly qualified as such under the laws of the states in which the
Mortgaged Properties are located if such qualification is necessary to issue the applicable insurance policy or bond, duly
authorized and licensed in such states to transact the applicable insurance business and to write the insurance provided by the
Primary Insurance Policies and approved as an insurer by the Master Servicer. A Qualified Insurer must have the rating required by
the Rating Agencies.


Rate Ceiling:  The maximum per annum Mortgage Interest Rate permitted under the related Mortgage Note.


Rating Agency:  Initially, each of S&P and Moody’s and thereafter, each nationally recognized statistical rating
organization that has rated the Certificates at the request of the Company, or their respective successors in interest.


Ratings:  As of any date of determination, the ratings, if any, of the Certificates as assigned by the applicable Rating
Agencies.


Realized Loss:  For any Distribution Date, with respect to any Mortgage Loan which became a Liquidated Mortgage Loan during the
related Prior Period, the sum of (i) the principal balance of such Mortgage Loan remaining outstanding and the principal portion of
Nonrecoverable Advances actually reimbursed with respect to such Mortgage Loan (the principal portion of such Realized Loss), and
(ii) the accrued interest on such Mortgage Loan remaining unpaid and the interest portion of Nonrecoverable Advances actually
reimbursed with respect to such Mortgage Loan (the interest portion of such Realized Loss); provided, however, that
for purposes of allocating Realized Losses to the REMIC I and REMIC II Regular Interests pursuant to this definition of
“Realized Loss,” the aggregate principal portion of Realized Losses for any Distribution Date shall be reduced by the
Cumulative Carry-Forward Subsequent Recoveries Amount for such Distribution Date. For any Distribution Date, with respect to any
Mortgage Loan which is not a Liquidated Mortgage Loan, the amount of the Bankruptcy Loss incurred with respect to such Mortgage
Loan as of the related Due Date.


Realized Losses shall be allocated among the REMIC I Regular Interests
as follows:  The interest portion of Realized Losses, if any, shall be allocated among the Class LT1, Class LT2, Class LT3 and
Class LT4  Regular Interests pro rata according to the amount of interest accrued but unpaid thereon, in reduction
thereof.  Any interest portion of Realized Losses in excess of the amount allocated pursuant to the preceding sentence shall
be treated as a principal portion of Realized Losses and allocated pursuant to the succeeding sentence.  The principal portion
of Realized Losses, if any, shall be allocated (a) first, to the Class LT2, Class LT3 and Class LT4 Regular Interests, pro rata
according to the Principal Reduction Amount thereof, to the extent of such Principal Reduction Amount in reduction of the Class
Principal Balance of such Regular Interest, (b) second, to the Class LT1 Regular Interest, in reduction of the Class Principal
Balance thereof, and (c) third, to the Class LT2, Class LT3 and Class LT4 Regular Interests, pro rata according to the Class
Principal Balance thereof remaining after the application of clause (a) above, in reduction thereof.  


Realized Losses shall be allocated among the REMIC II Regular
Interests (i) for Realized Losses allocable to principal (a) first, to the Class B-6-L Regular Interest, until the Class B-6-L
Principal Balance has been reduced to zero, (b) second, to the Class B-5-L Regular Interest, until the Class B-5-L Principal
Balance has been reduced to zero, (c) third, to the Class B-4-L Regular Interest, until the Class B-4-L Principal Balance has been
reduced to zero, (d) fourth, to the Class B-3-L Regular Interest, until the Class B-3-L Principal Balance has been reduced to
zero, (e) fifth, to the Class B-2-L Regular Interest, until the Class B-2-L Principal Balance has been reduced to zero, (f) sixth,
to the Class B-1-L Regular Interest, until the Class B-1-L Principal Balance has been reduced to zero and (g) seventh, to the Class
A-L and Class X-L Regular Interests, pro rata according to the Class Principal Balances thereof, in reduction thereof; and (ii) for
Realized Losses allocable to interest (a) first, to the Class B-6-L Regular Interest, in reduction of accrued but unpaid interest
thereon and then in reduction of the Class B-6-L Principal Balance, (b) second, to the Class B-5-L Regular Interest, in reduction
of accrued but unpaid interest thereon and then in reduction of the Class B-5-L Principal Balance, (c) third, to the Class B-4-L
Regular Interest, in reduction of accrued but unpaid interest thereon and then in reduction of the Class B-4-L Principal Balance,
(d) fourth, to the Class B-3-L Regular Interest, in reduction of accrued but unpaid interest thereon and then in reduction of the
Class B-3-L Principal Balance, (e) fifth, to the Class B-2-L Regular Interest, in reduction of accrued but unpaid interest thereon
and then in reduction of the Class B-2-L Principal Balance, (f) sixth, to the Class B-1-L Regular Interest, in reduction of accrued
but unpaid interest thereon and then in reduction of the Class B-1-L Principal Balance and (g) seventh, to the Class A-L and Class
X-L Regular Interests, pro rata according to accrued but unpaid interest on such Classes, in reduction thereof, and then to such
Classes, pro rata according to the Class Principal Balances thereof, in reduction thereof; provided, however, that (1) until
the Class A-1B-L Principal Balance has been reduced to zero, all principal losses that would otherwise be allocated to the Class
A-1A-L Regular Interest pursuant to clause (i) of this paragraph shall instead be allocated to the Class A-1B-L Regular Interest,
in reduction of the Class A-B-L Principal Balance, and all interest losses that would otherwise be allocated to the Class A-1A-L
Regular Interest pursuant to clause (ii) of this paragraph shall instead be allocated to the Class A-1B-L Regular Interest, in
reduction of accrued but unpaid interest thereon, and then in reduction of the Class A-1B-L Principal Balance and (2) until the
Class A-2B-L Principal Balance has been reduced to zero, all principal losses that would otherwise be allocated to the Class
A-2A1-L, Class A-2A2-L or Class A-2A3-L Regular Interests pursuant to clause (i) of this paragraph shall instead be allocated to
the Class A-2B-L Regular Interest, in reduction of the Class A-2B-L Principal Balance, and all interest losses that would otherwise
be allocated to the Class A-2A1-L, Class A-2A2-L or Class A-2A3-L Regular Interests pursuant to clause (ii) of this paragraph shall
instead be allocated to the Class A-2B-L Regular Interest, in reduction of accrued but unpaid interest thereon, and then in
reduction of the Class A-2B-L Principal Balance.


On each Distribution Date, after giving effect to the principal
distributions and allocations of losses and Net Negative Amortization Amounts as provided in this Agreement (without regard to this
paragraph), if the aggregate Class Principal Balance of all outstanding Classes of REMIC II Regular Interests and the Class R-1
Residual Interest (plus any Cumulative Carry-Forward Subsequent Recoveries Amount for such Distribution Date) exceeds the aggregate
principal balance of the Mortgage Loans remaining to be paid at the close of business on the Cut-Off Date, after deduction of (i)
all principal payments due on or before the Cut-Off Date in respect of each Mortgage Loan whether or not paid, and (ii) all amounts
of principal in respect of each Mortgage Loan that have been received or advanced and included in the REMIC II Available
Distribution Amount and all losses in respect of each Mortgage Loan that have been allocated to the REMIC II Regular Interests on
such Distribution Date or prior Distribution Dates, and after giving effect to all Negative Amortization Amounts in respect of each
Mortgage Loan that have been added to the principal balance of such Mortgage Loan prior to such Distribution Date, then such excess
will be deemed a principal loss and will be allocated to the most junior Class of Class B-L Regular Interests, in reduction of the
Class Principal Balance thereof.


Recognition Agreement:  With respect to a Cooperative Loan, the recognition agreement between the Cooperative and the originator of
such Cooperative Loan.


Record Date:  The last Business Day of the month immediately preceding the month of the related Distribution Date.


Regular Interests:  (i) With respect to REMIC I, the REMIC I Regular Interests and (ii) with respect to REMIC II, the REMIC II
Regular Interests.


Relief Act Shortfall:  For any Distribution Date for any Mortgage Loan with respect to which the Servicemembers Civil Relief Act,
formerly known as the Soldiers’ and Sailors’ Civil Relief Act of 1940, or any comparable state legislation
(collectively, the “Relief Act”), limits the amount of interest payable by the related Mortgagor, an amount
equal to one month’s interest on such Mortgage Loan at an annual interest rate equal to the excess, if any, of (i) the annual
interest rate at which interest otherwise accrued during the Prior Period under the terms of the related Mortgage Note over (ii)
the annual interest rate at which interest accrued during the Prior Period by application of the Relief Act.


Reference Banks: As defined in Section 3.19(b).


REMIC:  A real estate mortgage investment conduit, as such term is defined in the Code.


REMIC Provisions:  Sections 860A through 860G of the Code, related Code provisions and regulations promulgated thereunder, as
the foregoing may be in effect from time to time.


REMIC I:  The segregated pool of assets of the Trust consisting of the REMIC I Assets, which shall be a REMIC pursuant to the
Code, with respect to which a separate REMIC election is to be made and the beneficial interests in which shall be the REMIC I
Regular Interests and the Class R-1 Residual Interest.


REMIC I Assets:  All of the Mortgage Pool Assets.


REMIC I Available Distribution Amount:  For any Distribution Date, the sum of the following amounts with respect to the Mortgage
Loans:


(1)        the total amount of all
cash received by or on behalf of the Master Servicer with respect to such Mortgage Loans by the Determination Date for such
Distribution Date and not previously distributed, including Monthly P&I Advances made by Servicers, Liquidation Proceeds and
scheduled amounts of distributions from Buydown Funds respecting Buydown Loans, if any, except:


(a)       
all scheduled payments of principal and interest collected but due subsequent to such Distribution Date;


(b)       
all Curtailments received after the Prior Period;


(c)       
all Payoffs received after the Payoff Period immediately preceding such Distribution Date (together with any interest payment
received with such Payoffs to the extent that it represents the payment of interest accrued on the Mortgage Loans for the period
subsequent to the Prior Period), and interest which was accrued and received on Payoffs received during the period from the 1st to
the 14th day of the month of such Distribution Date, which interest shall not be included in the calculation of the REMIC I
Available Distribution Amount for any Distribution Date;


(d)       
Insurance Proceeds, Liquidation Proceeds and Subsequent Recoveries received on such Mortgage Loans after the Prior
Period;


(e)       
all amounts in the Certificate Account which are due and reimbursable to a Servicer or the Master Servicer pursuant to the terms of
this Agreement;


(f)         the sum of the Master Servicing Fee and the Servicing Fee for each such
Mortgage Loan, and any Special Primary Insurance Premium payable on such Distribution Date with respect to such Mortgage Loan;
and


(g)       
Excess Liquidation Proceeds;


(2)        the sum, to the extent
not previously distributed, of the following amounts, to the extent advanced or received, as applicable, by the Master
Servicer:


(a)       
any Monthly P&I Advance made by the Master Servicer to the Trustee with respect to such Distribution Date relating to such
Mortgage Loans; and


(b)       
Compensating Interest; and


(3)        the total amount of any
cash received during the Prior Period by the Trustee or the Master Servicer in respect of a Purchase Obligation under Section 2.07
and Section 2.08 or any permitted purchase of such a Mortgage Loan.


REMIC I Distribution Amount:  For any Distribution Date, the REMIC I Available Distribution Amount for such Distribution Date
shall be distributed to the REMIC I Regular Interests and the Class R-1 Residual Interest in the following amounts and priority, to
the extent of the REMIC I Available Distribution Amount for such Distribution Date:


(i)         first, to the Class LT1, Class LT2 and Class LT4 Regular Interests and
the Class R-1 Residual Interest, concurrently, the sum of the Interest Distribution Amounts for such Classes remaining unpaid from
previous Distribution Dates, pro rata according to their respective shares of such unpaid amounts;


(ii)        second, to the Class LT1, Class LT2 and Class LT4 Regular Interests and the
Class R-1 Residual Interest, concurrently, the sum of the Interest Distribution Amounts for such Classes for the current
Distribution Date, pro rata according to their respective Interest Distribution Amounts;


(iii)       third, to the Class R-1 Residual Interest, until the Class Principal Balance
thereof has been reduced to zero;


(iv)       fourth, to the REMIC I Regular Interests, as principal, the REMIC I Principal
Distribution Amount, sequentially as follows:


(a)        first, to the Class LT2, Class LT3 and Class LT4 Regular Interests, the Class
LT2 Principal Distribution Amount, the Class LT3 Principal Distribution Amount and the Class LT4 Principal Distribution Amount,
respectively;


(b)        second, to the Class LT1 Regular Interest, until its Class Principal Balance
has been reduced to zero; and


(c)        third, to the Class LT2, Class LT3 and Class LT4 Regular Interests, pro rata
according to Class Principal Balance, until their respective Class Principal Balances have been reduced to zero;


(v)        fifth, to each Class of REMIC I Regular Interests, pro rata according to the
amount of unreimbursed Realized Losses allocable to principal previously allocated to each such Class, the aggregate amount of any
distributions to the REMIC II Regular Interests pursuant to paragraph (I)(xxii) of the definition of “REMIC II Distribution
Amount” on such Distribution Date; provided, however, that any amounts distributed pursuant to this paragraph (v) of
this definition of “REMIC I Distribution Amount” shall not cause a reduction in the Class Principal Balances of any of
the REMIC I Regular Interests; and


(vi)       sixth, to the Class R-1 Residual Interest, the Residual Distribution Amount for the
Class R-1 Residual Interest for such Distribution Date.


REMIC I Principal Distribution Amount:  For any Distribution Date, an amount equal to the sum of (a) the Principal Payment Amount
for such Distribution Date, (b) the Principal Prepayment Amount for such Distribution Date, (c) the aggregate of Liquidation
Principal for all Mortgage Loans which became Liquidated Mortgage Loans during the Prior Period and (d) any Subsequent Recoveries
for such Distribution Date.


REMIC I Regular Interests:  The Classes of undivided beneficial interests in REMIC I designated as “regular interests”
in the table titled “REMIC I Interests” in the Preliminary Statement hereto.  The REMIC I Regular Interests,
together with the Class R-1 Residual Interest, shall be deemed to be a separate series of beneficial interests in the assets of the
Trust consisting of the REMIC I Assets pursuant to Section 3806(b)(2) of the Statutory Trust Statute.


REMIC II:  The segregated pool of assets of the Trust consisting of the REMIC II Assets, which shall be a REMIC pursuant to the
Code, with respect to which a separate REMIC election is to be made, and the beneficial interests in which shall be the REMIC II
Regular Interests and the Class R-2 Residual Interest.


REMIC II Assets:  The REMIC I Regular Interests.


REMIC II Available Distribution Amount:  For any Distribution Date, the aggregate of all distributions to the REMIC I Regular
Interests (which amount shall be available for distributions to the REMIC II Regular Interests and the Class R-2 Residual Interest
as provided herein).


REMIC II Distribution Amount:  (I) For any Distribution Date prior to the Credit Support Depletion Date, the REMIC II Available
Distribution Amount for any Distribution Date shall be distributed to the REMIC II Regular Interests and the Class R-2 Residual
Interest in the following amounts and priority, to the extent of the REMIC II Available Distribution Amount for such Distribution
Date:


(i)         first, to the Class A-L and Class X-L Regular Interests and the Class
R‐1 Residual Interest, concurrently, the sum of the Interest Distribution Amounts for such Classes remaining unpaid from
previous Distribution Dates, pro rata according to their respective shares of such unpaid amounts;


(ii)        second, to the Class A-L and Class X-L Regular Interests and the Class
R‐1 Residual Interest, concurrently, the sum of the Interest Distribution Amounts for such Classes for the current
Distribution Date, pro rata according to their respective Interest Distribution Amounts;


(iii)       third, to the Class A-L and Class X-L Regular Interests, as principal, the Senior
Principal Distribution Amount (reduced by $100 for the first Distribution Date), sequentially, as follows:


(a)        first, concurrently, as follows:


            (1) 25.6343333946% to the Class A-1A-L Regular Interest,
until the Class A-1A-L Principal Balance has been reduced to zero;


            (2) 17.0901522987% to the Class A-1B-L Regular Interest,
until the Class A-1B-L Principal Balance has been reduced to zero;


            (3) 27.3528361920% to the Class A-2A1-L Regular Interest,
until the Class A-2A1-L Principal Balance has been reduced to zero;


            (4) 18.2869820907%, sequentially, as follows:


(A)       to
the Class A-2A2-L Regular Interest, until the Class A-2A2-L Principal Balance has been reduced to zero; and


(B)       to
the Class A-2A3-L Regular Interest, until the Class A-2A3-L Principal Balance has been reduced to zero;


            (5) 8.0554818628% to the Class A-2B-L Regular Interest,
until the Class A-2B-L Principal Balance has been reduced to zero; and


            (6) 3.5802141613% to the Class A-3-L Regular Interest,
until the Class A-3-L Principal Balance has been reduced to zero; and


(b)        second, to the Class X-L Regular Interest, until the Class X-L Principal
Balance has been reduced to zero;


(iv)       fourth,
to the Class B-1-L Regular Interest, the Interest Distribution Amount for such Class of Regular Interests remaining unpaid from
previous Distribution Dates;


(v)        fifth, to the Class B-1-L Regular Interest, the Interest Distribution Amount
for such Class of Regular Interests for the current Distribution Date;


(vi)       sixth, to the Class B-1-L Regular Interest, the portion of the Subordinate
Principal Distribution Amount allocable to such Class of Regular Interests pursuant to the definition of “Subordinate
Principal Distribution Amount,” until the Class B-1-L Principal Balance has been reduced to zero;


(vii)      seventh, to the Class B-2-L Regular Interest, the Interest Distribution Amount for such
Class of Regular Interests remaining unpaid from previous Distribution Dates;


(viii)      eighth, to the Class B-2-L Regular Interest, the Interest Distribution Amount for such
Class of Regular Interests for the current Distribution Date;


(ix)       ninth, to the Class B-2-L Regular Interest, the portion of the Subordinate
Principal Distribution Amount allocable to such Class of Regular Interests pursuant to the definition of “Subordinate
Principal Distribution Amount,” until the Class B-2-L Principal Balance has been reduced to zero;


(x)        tenth, to the Class B-3-L Regular Interest, the Interest Distribution Amount
for such Class of Regular Interests remaining unpaid from previous Distribution Dates;


(xi)       eleventh, to the Class B-3-L Regular Interest, the Interest Distribution Amount for
such Class of Regular Interests for the current Distribution Date;


(xii)      twelfth, to the Class B-3-L Regular Interest, the portion of the Subordinate Principal
Distribution Amount allocable to such Class of Regular Interests pursuant to the definition of “Subordinate Principal
Distribution Amount,” until the Class B-3-L Principal Balance has been reduced to zero;


(xiii)      thirteenth, to the Class B-4-L Regular Interest, the Interest Distribution Amount for
such Class of Regular Interests remaining unpaid from previous Distribution Dates;


(xiv)     fourteenth, to the Class B-4-L Regular Interest, the Interest Distribution Amount for such
Class of Regular Interests for the current Distribution Date;


(xv)      fifteenth, to the Class B-4-L Regular Interest, the portion of the Subordinate Principal
Distribution Amount allocable to such Class of Regular Interests pursuant to the definition of “Subordinate Principal
Distribution Amount,” until the Class B-4-L Principal Balance has been reduced to zero;


(xvi)     sixteenth, to the Class B-5-L Regular Interest, the Interest Distribution Amount for such
Class of Regular Interests remaining unpaid from previous Distribution Dates;


(xvii)     seventeenth, to the Class B-5-L Regular Interest, the Interest Distribution Amount for such
Class of Regular Interests for the current Distribution Date;


(xviii)   
eighteenth, to the Class B-5-L Regular Interest, the portion of the Subordinate Principal Distribution Amount allocable to such
Class of Regular Interests pursuant to the definition of “Subordinate Principal Distribution Amount,” until the Class
B-5-L Principal Balance has been reduced to zero;


(xix)     nineteenth, to the Class B-6-L Regular Interest, the Interest Distribution Amount for such
Class of Regular Interests remaining unpaid from previous Distribution Dates;


(xx)      twentieth, to the Class B-6-L Regular Interest, the Interest Distribution Amount for such
Class of Regular Interests for the current Distribution Date;


(xxi)     twenty-first, to the Class B-6-L Regular Interest, the portion of the Subordinate Principal
Distribution Amount allocable to such Class of Regular Interests pursuant to the definition of “Subordinate Principal
Distribution Amount,” until the Class B-6-L Principal Balance has been reduced to zero;


(xxii)     twenty-second, to the outstanding Classes of REMIC II Regular Interests in the order of
seniority (which, from highest to lowest, shall be as follows: the Class A-L and Class X-L Regular Interests of equal seniority,
and then Class B-1-L, Class B-2-L, Class B-3-L, Class B-4-L, Class B-5-L and Class B-6-L of decreasing seniority) the remaining
portion, if any, of the REMIC II Available Distribution Amount, up to the amount of unreimbursed Realized Losses allocable to
principal previously allocated or to be allocated on such Distribution Date to such Class, if any; provided, however, that
in the case of Classes of equal seniority, the amount distributable to such Classes shall be allocated among such Classes according
to the amount of losses allocated thereto; provided, further, that any amounts distributed pursuant to this paragraph
(I)(xxii) of this definition of “REMIC II Distribution Amount” shall not cause a reduction in the Class Principal
Balances of any of the Classes of REMIC II Regular Interests; and


(xxiii)   
twenty-third, to the Class R-1 Residual Interest, the Residual Distribution Amount for the Class R-1 Residual Interest for such
Distribution Date.


(II)       For any Distribution Date on
or after the Credit Support Depletion Date, the REMIC II Available Distribution Amount for such Distribution Date shall be
distributed to the outstanding Classes of REMIC II Regular Interests and the Class R-2 Residual Interest in the following amounts
and priority, to the extent of the REMIC II Available Distribution Amount for such Distribution Date:


(i)         first, to the Class A-L and Class X-L Regular Interests, the amount
payable to each such Class of Regular Interests on prior Distribution Dates pursuant to clause (I)(ii) or (II)(ii) of this
definition of “REMIC II Distribution Amount,” and remaining unpaid, pro rata according to such amount payable to the
extent of amounts available;


(ii)        second, to the Class A-L and Class X-L Regular Interests, concurrently, the
sum of the Interest Distribution Amounts for such Classes of Regular Interests for the current Distribution Date, pro rata
according to their respective Interest Distribution Amounts;


(iii)       third, to the Class A-L and Class X-L Regular Interests, pro rata according to
Class Principal Balance, as principal, the Senior Principal Distribution Amount; and


(iv)       fourth, to the Class R-2 Residual Interest, the Residual Distribution Amount for
the Class R-2 Residual Interest for such Distribution Date.


REMIC II Regular Interests:  The Classes of undivided beneficial interests in REMIC II designated as “regular interests”
in the table titled “REMIC II Interests” in the Preliminary Statement hereto.  The REMIC II Regular Interests,
together with the Class R-2 Residual Interest, shall be deemed to be a separate series of beneficial interests in the assets of the
Trust consisting of the REMIC II Assets pursuant to Section 3806(b)(2) of the Statutory Trust Statute.


Residual Certificates:  The Class R Certificates.


Residual Distribution Amount:  For any Distribution Date, with respect to the Class R-1 Residual Interest, any portion of the
REMIC I Available Distribution Amount remaining after all distributions of the REMIC I Available Distribution Amount pursuant to
the definition of “REMIC I Distribution Amount” (other than the distributions pursuant to the last clause
thereof).


For any Distribution Date, with respect to the Class R-2 Residual
Interest, any portion of the REMIC II Available Distribution Amount remaining after all distributions of the REMIC II Available
Distribution Amount pursuant to the definition of “REMIC II Distribution Amount” (other than the distributions pursuant
to the last clause thereof).


Upon termination of the obligations created by this Agreement and
liquidation of REMIC I and REMIC II, the amounts which remain on deposit in the Certificate Account after payment to the Holders of
the REMIC I Regular Interests of the amounts set forth in Section 9.01 of this Agreement, and subject to the conditions set forth
therein, shall be distributed to the Class R-1 and Class R-2 Residual Interests in accordance with the preceding sentences of this
definition as if the date of such distribution were a Distribution Date.


Responsible Officer:  When used with respect to the Trustee or the Delaware Trustee, any officer assigned to and working in the
Corporate Trust Office (in the case of the Trustee) or its corporate trust office (in the case of the Delaware Trustee) or, in each
case, in a similar group and also, with respect to a particular matter, any other officer to whom such matter is referred because
of such officer’s knowledge of and familiarity with the particular subject.


ROV Mortgage Loan:  A Mortgage Loan with respect to which the value set forth on the appraisal has been appealed and, as a
result, an internal valuation has been conducted and included in a residential appraisal review contained in the related credit
file.


S&P:  Standard & Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc., provided that at any time
it be a Rating Agency.


Secretary of State:  The Secretary of State of the State of Delaware.


Securities Act:  The Securities Act of 1933, as amended.


Security Agreement:  With respect to a Cooperative Loan, the agreement or mortgage creating a security interest in favor of the
originator of the Cooperative Loan in the related Cooperative Stock.


Selling and Servicing Contract:  (a) The contract (including the Washington Mutual Mortgage Securities Corp. Selling Guide and
Washington Mutual Mortgage Securities Corp. Servicing Guide to the extent incorporated by reference therein) between the Company
and a Person relating to the sale of the Mortgage Loans to the Company and the servicing of such Mortgage Loans for the benefit of
the Certificateholders, which contract is substantially in the form of Exhibit E hereto, as such contract may be amended or
modified from time to time; provided, however, that any such amendment or modification shall not materially adversely affect
the interests and rights of Certificateholders or (b) any other similar contract, including any mortgage loan purchase and
servicing agreement or any assignment, assumption and recognition agreement related to a mortgage loan purchase and sale agreement,
providing substantially similar rights and benefits as those provided by the forms of contract attached as Exhibit E
hereto.


Senior Certificates:  The Class A, Class X and Class R Certificates.


Senior Liquidation Amount:  For any Distribution Date, the sum of (A) the aggregate, for each Mortgage Loan which became a
Liquidated Mortgage Loan during the Prior Period, of the lesser of: (i) the Senior Percentage of the Principal Balance of such
Mortgage Loan and (ii) the Senior Prepayment Percentage of the Liquidation Principal with respect to such Mortgage Loan and (B) the
Senior Prepayment Percentage of any Subsequent Recoveries for such Distribution Date.


Senior Percentage:  For any Distribution Date, the aggregate Class Principal Balance of the Class A, Class X and Residual
Certificates divided by the aggregate Class Principal Balance of the Class A, Class B, Class X and Residual Certificates, in each
case immediately before such Distribution Date.


Senior Prepayment Percentage: Subject to the immediately succeeding paragraph, (A) for any Distribution Date prior to the tenth
anniversary of the first Distribution Date, the Senior Prepayment Percentage shall equal 100% and (B) for any Distribution Date on
or after the tenth anniversary of the first Distribution Date, the Senior Prepayment Percentage shall be calculated as follows: (1)
for any such Distribution Date on or after the tenth anniversary but before the eleventh anniversary of the first Distribution
Date, the Senior Percentage for such Distribution Date plus 70% of the Subordinate Percentage for such Distribution Date; (2) for
any such Distribution Date on or after the eleventh anniversary but before the twelfth anniversary of the first Distribution Date,
the Senior Percentage for such Distribution Date plus 60% of the Subordinate Percentage for such Distribution Date; (3) for any
such Distribution Date on or after the twelfth anniversary but before the thirteenth anniversary of the first Distribution Date,
the Senior Percentage for such Distribution Date plus 40% of the Subordinate Percentage for such Distribution Date; (4) for any
such Distribution Date on or after the thirteenth anniversary but before the fourteenth anniversary of the first Distribution Date,
the Senior Percentage for such Distribution Date plus 20% of the Subordinate Percentage for such Distribution Date; and (5) for any
such Distribution Date thereafter, the Senior Percentage for such Distribution Date; provided, however, that (x) for any
Distribution Date on or prior to the Distribution Date in January 2008, if (i) the Subordinate Percentage for such
Distribution Date is greater than or equal to twice the Subordinate Percentage as of the Closing Date and (ii) cumulative Realized
Losses on the Mortgage Loans allocated to the Class B Certificates, as a percentage of the aggregate Class Principal Balance of the
Class B Certificates as of the Closing Date, do not exceed 20%, then the Senior Prepayment Percentage shall equal the Senior
Percentage for such Distribution Date plus 50% of the Subordinate Percentage for such Distribution Date and (y) for any
Distribution Date after the Distribution Date in January 2008, if (i) the Subordinate Percentage for such Distribution Date is
greater than or equal to twice the Subordinate Percentage as of the Closing Date and (ii) cumulative Realized Losses on the
Mortgage Loans allocated to the Class B Certificates, as a percentage of the aggregate Class Principal Balance of the Class B
Certificates as of the Closing Date, do not exceed 30%, then the Senior Prepayment Percentage shall equal the Senior Percentage for
such Distribution Date.


Notwithstanding the immediately preceding paragraph, (A) for any
Distribution Date, if the Senior Percentage for such Distribution Date is greater than the Senior Percentage as of the Closing
Date, then the Senior Prepayment Percentage shall equal 100%, (B) for any Distribution Date on or before the tenth anniversary of
the first Distribution Date, if any of the tests specified in clauses (a) and (b) below is met, then the Senior Prepayment
Percentage shall equal 100% and (C) for any Distribution Date after the tenth anniversary of the first Distribution Date, if any of
the tests specified in clauses (a) and (b) below is met (unless either (x) the Senior Percentage for such Distribution Date is
greater than the Senior Percentage as of the Closing Date or (y) there is no Earlier Distribution Date (as defined below), in each
of which case the Senior Prepayment Percentage shall equal 100%), then the Senior Prepayment Percentage shall be calculated as
follows:  (1) if the most recent preceding Distribution Date on which none of the tests specified in clauses (a) and (b) below
was met (such date referred to as the “Earlier Distribution Date”) is on or after the tenth anniversary but
before the eleventh anniversary of the first Distribution Date, then the Senior Prepayment Percentage shall equal the Senior
Percentage for the current Distribution Date plus 70% of the Subordinate Percentage for the current Distribution Date, (2) if the
Earlier Distribution Date is on or after the eleventh anniversary but before the twelfth anniversary of the first Distribution
Date, then the Senior Prepayment Percentage shall equal the Senior Percentage for the current Distribution Date plus 60% of the
Subordinate Percentage for the current Distribution Date, (3) if the Earlier Distribution Date is on or after the twelfth
anniversary but before the thirteenth anniversary of the first Distribution Date, then the Senior Prepayment Percentage shall equal
the Senior Percentage for the current Distribution Date plus 40% of the Subordinate Percentage for the current Distribution Date,
(4) if the Earlier Distribution Date is on or after the thirteenth anniversary but before the fourteenth anniversary of the first
Distribution Date, then the Senior Prepayment Percentage shall equal the Senior Percentage for the current Distribution Date plus
20% of the Subordinate Percentage for the current Distribution Date, and (5) if the Earlier Distribution Date is on or after the
fourteenth anniversary of the first Distribution Date, then the Senior Prepayment Percentage shall equal the Senior Percentage for
the current Distribution Date:


(a)        the mean aggregate Principal Balance, as of the Distribution Date in each of
the immediately preceding six calendar months, of the Mortgage Loans which were 60 or more days delinquent as of such date
(including Mortgage Loans in bankruptcy or foreclosure and Mortgaged Properties held by REMIC I) is greater than 50% of the
aggregate Class Principal Balance of the Class B Certificates as of the current Distribution Date, or


(b)        cumulative Realized Losses on the Mortgage Loans allocated to the Class B
Certificates, as a percentage of the aggregate Class Principal Balance of the Class B Certificates as of the Closing Date, are
greater than, for any Distribution Date (1) before the eleventh anniversary of the first Distribution Date, 30%, (2) on or after
the eleventh anniversary but before the twelfth anniversary of the first Distribution Date, 35%, (3) on or after the twelfth
anniversary but before the thirteenth anniversary of the first Distribution Date, 40%, (4) on or after the thirteenth anniversary
but before the fourteenth anniversary of the first Distribution Date, 45%, and (5) on or after the fourteenth anniversary of the
first Distribution Date, 50%.


If on any Distribution Date the allocation to the Class A and Class X
Certificates of Principal Prepayments in the percentage required would reduce the aggregate Class Principal Balance of such
Certificates below zero, the Senior Prepayment Percentage for such Distribution Date shall be limited to the percentage necessary
to reduce such aggregate Class Principal Balance to zero.


Senior Principal Distribution Amount:  For any Distribution Date, an amount equal to the sum of (a) the Senior Percentage of the
Principal Payment Amount, (b) the Senior Prepayment Percentage of the Principal Prepayment Amount and (c) the Senior Liquidation
Amount.


Senior Subordinate Certificates:  The Subordinate Certificates other than the Junior Subordinate Certificates.


Servicer:  A mortgage loan servicing institution to which the Master Servicer has assigned servicing duties with respect to any
Mortgage Loan under a Selling and Servicing Contract; provided, however, the Master Servicer may designate itself or one or
more other mortgage loan servicing institutions as Servicer upon termination of an initial Servicer’s servicing
duties.


Servicing Fee:  For each Mortgage Loan, the monthly fee paid to the Servicer to perform primary servicing functions for the Master
Servicer with respect to such Mortgage Loan, equal to 1/12 of the product of (i) the Servicing Fee Rate for such Mortgage Loan and
(ii) the outstanding Principal Balance of such Mortgage Loan.  In addition, any prepayment penalty received on a Mortgage Loan
will be paid as additional servicing compensation to the Master Servicer or the related Servicer.


Servicing Fee Rate: For each Mortgage Loan, the per annum rate payable to the Servicer, as set forth for such Mortgage Loan in the
Mortgage Loan Schedule, equal to 0.375%.


Servicing Officer:  Any officer of the Master Servicer (or of the Servicer, but only with respect to the Custodial Agreement)
involved in, or responsible for, the administration and servicing of the Mortgage Loans or the Certificates, as applicable, whose
name and specimen signature appear on a list of servicing officers furnished to the Trustee by the Master Servicer, as such list
may from time to time be amended.


Special Primary Insurance Policy:  Any Primary Insurance Policy covering a Mortgage Loan the premium of which is payable by the
Trustee pursuant to Section 4.04(a), if so identified in the Mortgage Loan Schedule. There are no Special Primary Insurance
Policies with respect to any of the Mortgage Loans.


Special Primary Insurance Premium:  With respect to any Special Primary Insurance Policy, the monthly premium payable
thereunder.


Statutory Trust Statute:  Chapter 38 of Title 12 of the Delaware Code, 12 Del.C. §3801 et seq., as the same
may be amended from time to time.


Streamlined Mortgage Loan:  A Mortgage Loan originated in connection with the refinance of a mortgage loan pursuant to the related
seller’s, under the related Selling and Servicing Contract by which the Company acquired the Mortgage Loan, streamlined loan
documentation program then in effect.


Subordinate Certificates:  The Class B Certificates.


Subordinate Liquidation Amount:  For any Distribution Date, the excess, if any, of the sum of (A) the aggregate of Liquidation
Principal for all Mortgage Loans which became Liquidated Mortgage Loans during the Prior Period and (B) any Subsequent Recoveries
for such Distribution Date, over the Senior Liquidation Amount for such Distribution Date.


Subordinate Percentage:  For any Distribution Date, the excess of 100% over the Senior Percentage for such date.


Subordinate Prepayment Percentage:  For any Distribution Date, the excess of 100% over the Senior Prepayment Percentage for
such Distribution Date; provided, however, that if the aggregate Class Principal Balance of the Class A, Class X and
Residual Certificates has been reduced to zero, then the Subordinate Prepayment Percentage shall equal 100%.


Subordinate Principal Distribution
Amount:  For any Distribution Date, the sum of (i) the Subordinate Percentage
of the Principal Payment Amount, (ii) the Subordinate Principal Prepayments Distribution Amount and (iii) the Subordinate
Liquidation Amount.


For any Distribution Date, the Subordinate Principal Distribution
Amount shall be allocated pro rata, by Class Principal Balance, among the Classes of Class B-L Regular Interests and paid in the
order of distribution to such Classes pursuant to the definition of “REMIC II Distribution Amount” except as otherwise
stated in such definition. Notwithstanding the foregoing, for any Distribution Date prior to distributions on such date, if the
Subordination Level for any Class or Classes of Class B-L Regular Interests is less than such Subordination Level as of the Closing
Date, then the pro rata portion of the Subordinate Principal Prepayments Distribution Amount, if any, otherwise allocable to such
Class or Classes of Class B-L Regular Interests shall be allocated to the more senior Classes of Class B-L Regular Interests, pro
rata according to the Class Principal Balances of such Classes.  For purposes of this definition and the definition of
“Subordination Level,” the relative seniority, from highest to lowest, of the Class B-L Regular Interests shall be as
follows: Class B-1-L, Class B-2-L, Class B-3-L, Class B-4-L, Class B-5-L and Class B-6-L.


Subordinate Principal Prepayments Distribution
Amount:  For any Distribution Date, the Subordinate Prepayment Percentage of
the Principal Prepayment Amount.


Subordination Level:  On any specified date, with respect to any Class of Class B-L Regular Interests, the percentage obtained by
dividing the aggregate Class Principal Balance of such Class and the Classes of Class B-L Regular Interests which are subordinate
in right of payment to such Class by the aggregate Class Principal Balance of the REMIC II Regular Interests and the Class R-1
Residual Interest as of such date prior to giving effect to distributions of principal and interest, allocations of Realized Losses
and allocations of Net Negative Amortization Amounts on such date.


Subsequent Recoveries: For any Distribution Date, amounts received by the Master Servicer during the Prior Period (after
deduction of amounts reimbursable under Section 3.05(a)(i) and (ii)) in connection with the liquidation of defaulted Mortgage Loans
after such Mortgage Loans became Liquidated Mortgage Loans, for each such Mortgage Loan up to the amount of Realized Losses, if
any, previously allocated in respect of such Mortgage Loan in reduction of the Class Principal Balance of any Class of
Certificates.


Substitute Mortgage Loan:  A Mortgage Loan which is substituted for another Mortgage Loan pursuant to and in accordance with the
provisions of Section 2.07.


Tax Matters Person:  With respect to each of REMIC I and REMIC II, a Holder of a Class R Certificate with a Percentage Interest
of at least 0.01% or any Permitted Transferee of such Class R Certificateholder designated as succeeding to the position of Tax
Matters Person in a notice to the Trustee signed by authorized representatives of the transferor and transferee of such Class R
Certificate. The Company is hereby appointed to act as the Tax Matters Person for REMIC I and REMIC II so long as it holds a Class
R Certificate with a Percentage Interest of at least 0.01%. The Company is hereby appointed to act as agent for the Tax Matters
Person for REMIC I and REMIC II, to perform the functions of such Tax Matters Person as provided herein, so long as the Company is
the Master Servicer hereunder, in the event that the Company ceases to hold a Class R Certificate with the required Percentage
Interest. In the event that the Company ceases to be the Master Servicer hereunder, the successor Master Servicer is hereby
appointed to act as agent for the Tax Matters Person for REMIC I and REMIC II, to perform the functions of such Tax Matters Person
as provided herein. If the Tax Matters Person for REMIC I and REMIC II becomes a Disqualified Organization, the last preceding
Holder, that is not a Disqualified Organization, of the Class R Certificate held by the Disqualified Organization shall be Tax
Matters Person pursuant to and as permitted by Section 5.01(c). If any Person is appointed as tax matters person by the Internal
Revenue Service pursuant to the Code, such Person shall be Tax Matters Person.


Termination Date:  The date upon which final payment of the Certificates will be made pursuant to the procedures set forth in
Section 9.01(b).


Termination Payment:  The final payment delivered to the Certificateholders on the Termination Date pursuant to the procedures
set forth in Section 9.01(b).


Transfer:  Any direct or indirect transfer or sale of any Ownership Interest in a Residual Certificate.


Transferee:  Any Person who is acquiring by Transfer any Ownership Interest in a Residual Certificate.


Transferee Affidavit and Agreement:  An affidavit and agreement in the form attached hereto as Exhibit J.


Trust:  WaMu Mortgage Pass-Through Certificates Series 2005-AR1 Trust, a Delaware statutory trust, created pursuant to this
Agreement.


Trustee:  Deutsche Bank National Trust Company, or its successor-in-interest as provided in Section 8.09, or any successor
trustee appointed as herein provided.


Uncollected Interest:  With respect to any Distribution Date for any Mortgage Loan on which a Payoff was made by a Mortgagor
during the related Payoff Period, except for Payoffs received during the period from the first through the 14th day of the month of
such Distribution Date, an amount equal to one month’s interest at the applicable Pass-Through Rate on such Mortgage Loan
less the amount of interest actually paid by the Mortgagor with respect to such Payoff.


Uncompensated Interest Shortfall:  For any Distribution Date, the sum of (i) the aggregate Relief Act Shortfall for such
Distribution Date, (ii) aggregate Curtailment Shortfall for such Distribution Date and (iii) the excess, if any, of (a) aggregate
Uncollected Interest for such Distribution Date over (b) Compensating Interest for such Distribution Date.


Uncompensated Interest Shortfall shall be allocated to the REMIC I
Regular Interests pro rata according to the amount of interest accrued on each such Class during the immediately preceding accrual
period, in reduction thereof.


Uncompensated Interest Shortfall shall be allocated to the REMIC II
Regular Interests pro rata according to the amount of interest accrued on each such Class during the related immediately preceding
accrual period, in reduction thereof.


Underwriters: Greenwich Capital Markets, Inc., WaMu Capital Corp. and Bear, Stearns & Co. Inc.


Underwriting Standards:  The underwriting standards of the Company, Washington Mutual Bank, FA or Washington Mutual Bank, a
Washington state chartered savings bank, as applicable.


Uninsured Cause:  Any cause of damage to a Mortgaged Property, the cost of the complete restoration of which is not fully
reimbursable under the hazard insurance policies required to be maintained pursuant to Section 3.07.


U.S. Person:  A citizen or resident of the United States, a corporation, partnership or other entity created or organized in or
under the laws of the United States, any state thereof or the District of Columbia, or an estate or trust that is subject to U.S.
federal income tax regardless of the source of its income.


VA:  The Department of Veterans Affairs, formerly known as the Veterans Administration, or any successor thereto.


Weighted Average Pass-Through Rate:  For any Distribution Date, the weighted average of the Pass-Through Rates on the Mortgage
Loans as of the second preceding Due Date (after giving effect to the payments due on the Mortgage Loans on that Due Date), as
determined for the accrual period for the related Class of Certificates.


Withdrawal Date:  Any day during the period commencing on the 18th day of the month of the related Distribution Date (or if such day
is not a Business Day, the immediately preceding Business Day) and ending on the last Business Day prior to the 21st day of the
month of such Distribution Date. The “related Due Date” for any Withdrawal Date is the Due Date immediately preceding
the related Distribution Date. 


Yield Maintenance Account:  The separate trust account maintained and held by the Trustee pursuant to Section 3.16, which account
shall bear a designation clearly indicating that the funds deposited therein are held in trust for the benefit of the Trust on
behalf of the Class A Certificateholders (other than the Class A-3 Certificateholders) and Class Y Certificateholders, and
which account provides that the Trustee may make, or cause to be made, withdrawals therefrom in accordance with Section
3.16.


Yield Maintenance Agreement:  The transactions evidenced by the ISDA Master Agreement dated as of January 18, 2005,
together with the related Schedule and Swap Confirmation and any other related documents thereto, between GCD and the Trustee,
which shall be an asset of the Trust.


Yield Maintenance Available Payment
Amount:  For any Distribution Date from and including March 2005 to and
including August 2013, the lesser of (a) the amounts received by the Trustee pursuant to the Yield Maintenance Agreement for such
Distribution Date and deposited by the Trustee into the Yield Maintenance Account in accordance with Section 3.16 and (b) a ratio,
the numerator of which is the actual number of days in the accrual period and the denominator of which is 360 of the product of (i)
the excess, if any, of (x) LIBOR, subject to a maximum of 10.10%, over (y) the related Cap Strike Rate and (ii) the lesser of
(a) the aggregate Class Principal Balance of the Class A Certificates (other than the Class A-3 Certificates) immediately
prior to such Distribution Date and (b) the related Yield Maintenance Notional Balance for such Distribution Date.


Yield Maintenance Notional Balance:  For any Distribution Date from and including March 2005 to and including August 2013,
shall mean the corresponding amount listed for such Distribution Date in Schedule 1 of the Prospectus.  After the Distribution
Date in August 2013, the Yield Maintenance Notional Balance will be equal to zero and the Yield Maintenance Agreement will be
terminated.


Yield Maintenance Payment:  For any Class of Class A Certificates (other than the Class A-3 Certificates) and for any
Distribution Date from and including March 2005 to and including August 2013, the lesser of (a) the Carryover Shortfall Amount for
such Class for such Distribution Date and (b) such Class’ pro rata share of the Yield Maintenance Available Payment Amount
for such Distribution Date (such pro rata share calculated based on an
allocation of such Yield Maintenance Available Payment Amount among the Classes of Class A Certificates
(other than the Class A-3 Certificates) pro rata according to Carryover Shortfall Amount).


For the Class Y Certificates for any Distribution Date from and
including March 2005 to and including August 2013, the sum of (A) the excess, if any, of (i) the Yield Maintenance Available
Payment Amount for such Distribution Date over (ii) the aggregate of the Yield Maintenance Payments for the Class A Certificates
for such Distribution Date and (B) the excess, if any, of (i) the amounts received by the Trustee pursuant to the Yield Maintenance
Agreement for such Distribution Date and deposited by the Trustee into the Yield Maintenance Account in accordance with Section
3.16 over (ii) the Yield Maintenance Available Payment Amount for such Distribution Date.


ARTICLE II



Creation of the Trust; Conveyance of the Mortgage Pool Assets and REMIC I Regular Interests; REMIC Election and Designations;
Original Issuance of Certificates


Section 2.01.        Creation of the Trust.  The Trust is hereby created and shall be known as “WaMu Mortgage Pass-Through Certificates Series 2005-AR1
Trust”. The purpose of the Trust is, and the Trust shall have the power and authority, to engage in the following activities,
all as provided by and subject to the terms of this Agreement:


(i)         to acquire, hold, lease, manage, administer, control, invest, reinvest,
operate and/or transfer the Mortgage Pool Assets, the REMIC II Assets and the Yield Maintenance Agreement;


(ii)        to issue the REMIC I Regular Interests, the REMIC II Regular Interests and
the Certificates;


(iii)       to make distributions to the REMIC I Regular Interests, the REMIC II Regular
Interests and the Certificates; and


(iv)       to engage in such other activities, including entering into agreements, as are
described in or required by the terms of this Agreement or as are necessary, suitable or convenient to accomplish the foregoing or
incidental thereto.


Deutsche
Bank National Trust Company is hereby appointed as a trustee of the Trust, to have all the rights, duties and obligations of the
Trustee with respect to the Trust hereunder, and Deutsche Bank National Trust Company hereby accepts such appointment and the Trust
created hereby.  Deutsche Bank Trust Company Delaware, is hereby appointed as a Delaware trustee of the Trust, to have all the
rights, duties and obligations of the Delaware Trustee with respect to the Trust hereunder, and Deutsche Bank Trust Company
Delaware, hereby accepts such appointment and the Trust created hereby.  It is the intention of the Company, the Trustee and
the Delaware Trustee that the Trust constitute a statutory trust under the Statutory Trust Statute, that this Agreement constitute
the governing instrument of the Trust, and that this Agreement amend and restate the Original Trust Agreement.  The parties
hereto acknowledge and agree that, prior to the execution and delivery hereof, the Delaware Trustee has filed the Certificate of
Trust. 


The assets of the Trust shall remain in the custody of the Trustee, on
behalf of the Trust, and shall be owned by the Trust except as otherwise expressly set forth herein.  Moneys to the credit of
the Trust shall be held by the Trustee and invested as provided herein.  All assets received and held in the Trust will not be
subject to any right, charge, security interest, lien or claim of any kind in favor of either of Deutsche Bank National Trust
Company or Deutsche Bank Trust Company Delaware in its own right, or any Person claiming through it.  Neither the Trustee nor
the Delaware Trustee, on behalf of the Trust, shall have the power or authority to transfer, assign, hypothecate, pledge or
otherwise dispose of any of the assets of the Trust to any Person, except as permitted herein.  No creditor of a beneficiary
of the Trust, of the Trustee, of the Delaware Trustee, of the Master Servicer or of the Company shall have any right to obtain
possession of, or otherwise exercise legal or equitable remedies with respect to, the property of the Trust, except in accordance
with the terms of this Agreement.


Section 2.02.        Restrictions on Activities of the Trust. Notwithstanding any other provision of this Agreement and any provision of law that otherwise so empowers
the Trust, so long as any Certificates are outstanding, the Trust shall not, and none of the Trustee, the Delaware Trustee, the
Company or the Master Servicer shall (except by amendment of this Agreement permitted by Section 10.01) knowingly cause the Trust
to, do any of the following:


(i)         engage in any business or activity other than those set forth in Section
2.01;


(ii)        incur or assume any indebtedness except for such indebtedness that may be
incurred by the Trust in connection with the execution or performance of this Agreement or any other agreement contemplated
hereby;


(iii)       guarantee or otherwise assume liability for the debts of any other
party;


(iv)       do any act in contravention of this Agreement or any other agreement contemplated
hereby to which the Trust is a party;


(v)        do any act which would make it impossible to carry on the ordinary business of
the Trust;


(vi)       confess a judgment against the Trust;


(vii)      possess or assign the assets of the Trust for other than a Trust purpose;


(viii)      cause the Trust to lend any funds to any entity, except as contemplated by this
Agreement; or


(ix)       change the purposes and powers of the Trust from those set forth in this
Agreement.


Section 2.03.        Separateness Requirements. Notwithstanding any other provision of this Agreement and any provision of law that otherwise so empowers the Trust, so
long as any Certificates are outstanding, the Trust shall perform the following:


(i)         except as expressly permitted by this Agreement or the Custodial
Agreement, maintain its books, records, bank accounts and files separate from those of any other Person;


(ii)        except as expressly permitted by this Agreement, maintain its assets in its
own separate name and in such a manner that it is not costly or difficult to segregate, identify, or ascertain such
assets;


(iii)       consider the interests of the Trust's creditors in connection with its
actions;


(iv)       hold itself out to creditors and the public as a legal entity separate and distinct
from any other Person and correct any known misunderstanding regarding its separate identity and refrain from engaging in any
activity that compromises the separate legal identity of the Trust;


(v)        prepare and maintain separate records, accounts and financial statements in
accordance with generally accepted accounting principles, consistently applied, and susceptible to audit.  To the extent it is
included in consolidated financial statements or consolidated tax returns, such financial statements and tax returns will reflect
the separateness of the respective entities and indicate that the assets of the Trust will not be available to satisfy the debts of
any other Person;


(vi)       allocate and charge fairly and reasonably any overhead shared with any other
Person;


(vii)      transact all business with affiliates on an arm’s-length basis and pursuant to
written, enforceable agreements;


(viii)      conduct business solely in the name of the Trust.  In that regard all written and
oral communications of the Trust, including, without limitation, letters, invoices, purchase orders and contracts, shall be made
solely in the name of the Trust (or the Trustee on behalf of the Trust);


(ix)       maintain a separate office through which its business shall be conducted, provided
that such office may be an office of the Trustee, which office shall not be shared with the Company or any affiliates of the
Company;


(x)        in the event that services have been or are in the future performed or paid by
any Person on behalf of the Trust (other than the Trustee, the Delaware Trustee, the Master Servicer or the Tax Matters Person as
permitted herein), reimburse such Person, as applicable, for the commercially reasonable value of such services or expenses
provided or incurred by such Person.  Accordingly, (i) the Trust shall reimburse such Person, as applicable, for the
commercially reasonable value of such services or expenses provided or incurred by such Person; (ii) to the extent invoices for
such services are not allocated and separately billed to the Trust, the amount thereof that was or is to be allocated and
separately billed to the Trust was or will be reasonably related to the services provided to the Trust; and (iii) any other
allocation of direct, indirect or overhead expenses for items shared between the Trust and any other Person, was or will be, to the
extent practicable, allocated on the basis of actual use or value of services rendered or otherwise on a basis reasonably related
to actual use or the value of services rendered;


(xi)       except as expressly permitted by this Agreement, not commingle its assets or funds
with those of any other Person;


(xii)      except as expressly permitted by this Agreement, not assume, guarantee, or pay the debts
or obligations of any other Person;


(xiii)      except as expressly permitted by this Agreement, not pledge its assets for the benefit
of any other Person;


(xiv)     not hold out its credit or assets as being available to satisfy the obligations of
others;


(xv)      pay its liabilities only out of its funds;


(xvi)     pay the salaries of its own employees, if any; and


(xvii)     cause the agents and other representatives of the Trust, if any, to act at all times with
respect to the Trust consistently and in furtherance of the foregoing.


None of the Trustee, the Delaware Trustee, the Company or the Master
Servicer shall (except by amendment of this Agreement permitted by Section 10.01) take any action that is inconsistent with the
purposes of the Trust or Section 2.02 or Section 2.03.  Neither the Company nor the Master Servicer shall (except by amendment
of this Agreement permitted by Section 10.01) direct the Trustee or the Delaware Trustee to take any action that is inconsistent
with the purposes of the Trust or Section 2.02 or Section 2.03.


Section 2.04.        Conveyance of Mortgage Pool Assets; Security Interest.


Concurrently with the execution and delivery hereof, the Company does
hereby irrevocably sell, transfer, assign, set over and otherwise convey to the Trust, without recourse, all the Company’s
right, title and interest in and to the Mortgage Pool Assets (such transfer and assignment by the Company to be referred to herein
as the “Conveyance”).


It is the express intent of the parties hereto that the Conveyance of
the Mortgage Pool Assets to the Trust by the Company as provided in this Section 2.04 be, and be construed as, an absolute sale of
the Mortgage Pool Assets. It is, further, not the intention of the parties that such Conveyance be deemed the grant of a security
interest in the Mortgage Pool Assets by the Company to the Trust to secure a debt or other obligation of the Company. However, in
the event that, notwithstanding the intent of the parties, the Mortgage Pool Assets are held to be the property of the Company, or
if for any other reason this Agreement is held or deemed to create a security interest in the Mortgage Pool Assets,
then:


(a)        this Agreement shall
constitute a security agreement;


(b)        the conveyance provided
for in this Section 2.04 shall be deemed to be a grant by the Company to the Trust of, and the Company hereby grants to the Trust,
to secure all of the Company’s obligations hereunder, a security interest in all of the Company’s right, title, and
interest, whether now owned or hereafter acquired, in and to:


(I)       
The Mortgage Pool Assets;


(II)       All
accounts, chattel paper, deposit accounts, documents, general intangibles, goods, instruments, investment property,
letter-of-credit rights, letters of credit, money, and oil, gas, and other minerals, consisting of, arising from, or relating to,
any of the foregoing; and


(III)      All
proceeds of the foregoing.


The Company shall file such financing statements, and the Company and
the Trustee acting on behalf of the Trust at the direction of the Company shall, to the extent consistent with this Agreement, take
such other actions as may be necessary to ensure that, if this Agreement were found to create a security interest in the Mortgage
Pool Assets, such security interest would be a perfected security interest of first priority under applicable law and will be
maintained as such throughout the term of the Agreement. In connection herewith, the Trust shall have all of the rights and
remedies of a secured party and creditor under the Uniform Commercial Code as in force in the relevant jurisdiction.


In the event that a pleading is filed in a court of competent
jurisdiction asserting that this Agreement creates a security interest in the Mortgage Pool Assets, the Trustee on behalf of the
Trust shall take actual possession of the Mortgage Pool Assets or, at the Company's option, the Trustee on behalf of the Trust
shall be provided an Opinion of Counsel addressed to the Trust and the Trustee reasonably satisfactory to the Trustee to the effect
that such security interest is a perfected security interest of first priority while the Mortgage Pool Assets are in the possession
of the Company or its affiliates.


Section 2.05.        Delivery of Mortgage Files.


In connection with the sale, transfer and assignment referred to in
Section 2.04, the Company, concurrently with the execution and delivery hereof, does deliver to, and deposit with, or cause to be
delivered to and deposited with, the Trustee or Custodian the Mortgage Files, which shall at all times be identified in the records
of the Trustee or the Custodian, as applicable, as being held by or on behalf of the Trust.


Concurrently with the execution and delivery hereof, the Company shall
cause to be filed the UCC assignment or amendment referred to in clause (Y)(vii) of the definition of “Mortgage
File.”  In connection with its servicing of Cooperative Loans, the Master Servicer will use its best efforts to file
timely continuation statements, if necessary, with regard to each financing statement and assignment relating to Cooperative
Loans.


In instances where the original recorded Mortgage or any intervening
assignment thereof (recorded or in recordable form) required to be included in the Mortgage File pursuant to the definition of
“Mortgage File” relating to a Mortgage Loan is not included in the Mortgage File delivered to the Trustee (or the
Custodian) prior to or concurrently with the execution and delivery hereof (due to a delay on the part of the recording office),
the Company shall deliver to the Trustee (or the Custodian) a fully legible reproduction (which may be in electronic form) of the
original Mortgage or intervening assignment provided that the originator, the related Lender or the escrow or title company which
provided closing services in connection with such Mortgage Loan certifies on the face of such reproduction(s) or copy as follows:
“Certified true and correct copy of original which has been transmitted for recordation.” For purposes hereof,
transmitted for recordation means having been mailed or otherwise delivered for recordation to the appropriate authority. In all
such instances, the Company shall transmit the original recorded Mortgage and any intervening assignments with evidence of
recording thereon (or a copy of such original Mortgage or intervening assignment certified by the applicable recording office)
(which may be in electronic form) (collectively, “Recording Documents”) to the Trustee (or the Custodian) within
270 days after the execution and delivery hereof. In instances where, due to a delay on the part of the recording office where any
such Recording Documents have been delivered for recordation, the Recording Documents cannot be delivered to the Trustee within 270
days after execution and delivery hereof, the Company shall deliver to the Trustee within such time period a certificate (a
“Company Officer’s Certificate”) signed by the Chairman of the Board, President, any Vice President or
Treasurer of the Company stating the date by which the Company expects to receive such Recording Documents from the applicable
recording office. In the event that Recording Documents have still not been received by the Company and delivered to the Trustee
(or the Custodian) by the date specified in its previous Company Officer’s Certificate delivered to the Trustee, the Company
shall deliver to the Trustee by such date an additional Company Officer’s Certificate stating a revised date by which the
Company expects to receive the applicable Recording Documents. This procedure shall be repeated until the Recording Documents have
been received by the Company and delivered to the Trustee (or the Custodian).


For Mortgage Loans for which the Company has received a Payoff after
the Cut-Off Date and prior to the date of execution and delivery hereof, the Company, in lieu of delivering the above documents,
herewith delivers to the Trustee a certification of a Servicing Officer of the nature set forth in Section 3.10.


The Trustee is authorized, with the Master Servicer’s consent,
to appoint any bank or trust company approved by each of the Company and the Master Servicer as Custodian of the documents or
instruments referred to in this Section 2.05 or in Section 2.10, and to enter into a Custodial Agreement for such purpose;
provided, however, that the Trustee shall be and remain liable for the acts of any such Custodian only to the extent that it
is responsible for its own acts hereunder.  Any documents delivered by the Company or the Master Servicer to the Custodian
shall be deemed to have been delivered to the Trustee for all purposes hereunder; and any documents held by the Custodian shall be
deemed to be held by the Trustee for all purposes hereunder.  There shall be a written Custodial Agreement between the Trustee
and each Custodian. Each Custodial Agreement shall contain an acknowledgment by the Custodian that all Mortgage Pool Assets,
Mortgage Files, and other documents and property held by it at any time are held by it for the benefit of the Trust. Pursuant to
the Initial Custodial Agreement, the Initial Custodian shall perform responsibilities of the Trustee with respect to the delivery,
receipt, examination and custody of the Mortgage Files on the Trustee’s behalf, as provided therein.


On or promptly after the Closing Date, the Master Servicer shall cause
the MERS® System to indicate that each MERS Loan, if any, has been assigned to “Deutsche Bank National Trust Company, as
Trustee, without recourse” or to “WaMu Mortgage Pass-Through Certificates Series 2005-AR1 Trust, without
recourse” by including in the MERS® System computer files (a) the code necessary to identify the Trustee and (b) the code
necessary to identify the series of the Certificates issued in connection with such Mortgage Loans; provided, however, that
in the event the Company acquired such Mortgage Loans from an affiliate of the Company, then the Master Servicer need not cause the
MERS® System to indicate such assignment.  The Master Servicer shall not alter the codes referenced in this paragraph with
respect to any MERS Loan during the term of this Agreement except in connection with an assignment of such MERS Loan or
de-registration thereof from the MERS® System in accordance with the terms of this Agreement.


Section 2.06.        REMIC Election for REMIC I.


The Tax Matters Person, shall, on behalf of REMIC I, elect to treat
REMIC I as a REMIC within the meaning of Section 860D of the Code and, if necessary, under applicable state laws. Such election
shall be included in the Form 1066 and any appropriate state return to be filed on behalf of REMIC I for its first taxable
year.


The Closing Date is hereby designated as the “startup day”
of REMIC I within the meaning of Section 860G(a)(9) of the Code.


The regular interests (as set forth in the table contained in the
Preliminary Statement hereto) relating to REMIC I are hereby designated as “regular interests” in REMIC I for purposes
of Section 860G(a)(1) of the Code. The Class R-1 Residual Interest is hereby designated as the sole class of “residual
interest” in REMIC I for purposes of Section 860G(a)(2) of the Code. The REMIC I Regular Interests and the Class R-1 Residual
Interest shall together be deemed to be a separate series of beneficial interests in the assets of the Trust consisting of the
REMIC I Assets pursuant to Section 3806(b)(2) of the Statutory Trust Statute.


The parties intend that the affairs of REMIC I shall constitute, and
that the affairs of  REMIC I shall be conducted so as to qualify REMIC I as a REMIC. In furtherance of such intention, the Tax
Matters Person shall, on behalf of REMIC I: (a) prepare and file, or cause to be prepared and filed, a federal tax return using a
calendar year as the taxable year and using an accrual method of accounting for REMIC I when and as required by the REMIC
Provisions and other applicable federal income tax laws; (b) make an election, on behalf of the trust, for REMIC I to be treated as
a REMIC on the federal tax return of  REMIC I for its first taxable year, in accordance with the REMIC Provisions; (c) prepare
and forward, or cause to be prepared and forwarded, to the Holders of the REMIC I Regular Interests and the Class R-1 Residual
Interest and the Trustee, all information reports as and when required to be provided to them in accordance with the REMIC
Provisions, and make available the information necessary for the application of Section 860E(e) of the Code; (d) conduct the
affairs of REMIC I at all times that any REMIC I Regular Interests are outstanding so as to maintain the status of REMIC I as a
REMIC under the REMIC Provisions; (e) not knowingly or intentionally take any action or omit to take any action that would cause
the termination of the REMIC status of REMIC I; and (f) pay the amount of any federal prohibited transaction penalty taxes imposed
on REMIC I when and as the same shall be due and payable (but such obligation shall not prevent the Company or any other
appropriate person from contesting any such tax in appropriate proceedings and shall not prevent the Company from withholding
payment of such tax, if permitted by law, pending the outcome of such proceedings); provided, that the Company shall be entitled to
be indemnified by REMIC I for any such prohibited transaction penalty taxes if the Company’s failure to exercise reasonable
care was not the primary cause of the imposition of such prohibited transaction penalty taxes.


The Trustee and the Master Servicer shall promptly provide the Company
with such information in the possession of the Trustee or the Master Servicer, respectively, as the Company may from time to time
request for the purpose of enabling the Company to prepare tax returns.  If so requested by the Tax Matters Person, the
Trustee shall sign tax returns on behalf of the REMICs.


In the event that a Mortgage Loan is discovered to have a defect
which, had such defect been discovered before the startup day, would have prevented such Mortgage Loan from being a
“qualified mortgage” within the meaning of Section 860G(a)(3) of the Code, and the Company does not repurchase such
Mortgage Loan within 90 days of such date, the Master Servicer, on behalf of the Trustee, shall within 90 days of the date such
defect is discovered sell such Mortgage Loan at such price as the Master Servicer in its sole discretion, determines to be the
greatest price that will result in the purchase thereof within 90 days of such date, unless the Master Servicer delivers to the
Trustee an Opinion of Counsel to the effect that continuing to hold such Mortgage Loan will not adversely affect the status of the
electing portion of REMIC I as a REMIC for federal income tax purposes.


In the event that any tax is imposed on “prohibited
transactions” of REMIC I as defined in Section 860F of the Code and not paid by the Company pursuant to clause (f) of the
third preceding paragraph, such tax shall be charged against amounts otherwise distributable to the Class R-1 Residual Interest.
Notwithstanding anything to the contrary contained herein, the Trustee is hereby authorized to retain from amounts otherwise
distributable to the Class R-1 Residual Interest on any Distribution Date sufficient funds to reimburse the Tax Matters Person (or
any agent therefor appointed in accordance with the definition of “Tax Matters Person” herein, if applicable), for the
payment of such tax (upon the written request of the Tax Matters Person or its agent, to the extent reimbursable, and to the extent
that the Tax Matters Person or its agent has not been previously reimbursed therefor).


Section
2.07.        Acceptance by Trustee. The Trustee
acknowledges receipt (or with respect to any Mortgage Loan subject to a Custodial Agreement, receipt by the Custodian thereunder)
on behalf of the Trust of the documents (or certified copies thereof as specified in Section 2.05) referred to in Section 2.05
above, but without having made the review required to be made within 45 days pursuant to this Section 2.07. The Trustee
acknowledges that all Mortgage Pool Assets, Mortgage Files, and related documents and property held by it at any time are held by
it as Trustee of the Trust for the benefit of the holders of the REMIC I Regular Interests and the Class R-1 Residual Interest. The
Trustee agrees, for the benefit of the Trust, to review (or cause the Initial Custodian to review) each Mortgage File within 45
days after the Closing Date and deliver to the Company a certification (or cause the Initial Custodian to deliver to the Company a
certification, which satisfies the applicable requirements of this Agreement; provided, however, that with respect to the Initial
Custodian Exhibit B-2 to the Initial Custodial Agreement is deemed to satisfy the applicable requirements of this Agreement) in the
form attached as Exhibit M hereto, to the effect that, except as noted, all documents required (in the case of instruments
described in clauses (X)(ii), (X)(iv) and (Y)(ix) of the definition of “Mortgage File,” known by the Trustee to be
required) pursuant to the definition of “Mortgage File” and Section 2.05 have been executed and received, and that such
documents relate to the Mortgage Loans identified in the Mortgage Loan Schedule. In performing such review, the Trustee may rely
upon the purported genuineness and due execution of any such document, and on the purported genuineness of any signature thereon.
The Trustee shall not be required to make any independent examination of any documents contained in each Mortgage File beyond the
review specifically required herein. The Trustee makes no representations as to: (i) the validity, legality, enforceability or
genuineness of any of the Mortgage Loans identified on the Mortgage Loan Schedule, or (ii) the collectability, insurability,
effectiveness or suitability of any Mortgage Loan. If the Trustee finds any document or documents constituting a part of a Mortgage
File not to have been executed or received, or to be unrelated to the Mortgage Loans identified in the Mortgage Loan Schedule, the
Trustee shall promptly so notify the Company. The Company hereby covenants and agrees that, if any such defect cannot be corrected
or cured, the Company shall, not later than 60 days after the Trustee’s notice to it respecting such defect, within the
three-month period commencing on the Closing Date (or within the two-year period commencing on the Closing Date if the related
Mortgage Loan is a “defective obligation” within the meaning of Section 860G(a)(4)(B)(ii) of the Code and Treasury
Regulation Section 1.860G-2(f)), either (i) repurchase the related Mortgage Loan from the Trust at the Purchase Price, or (ii)
substitute for any Mortgage Loan to which such defect relates a different mortgage loan (a “Substitute Mortgage
Loan”) which is a “qualified replacement mortgage” (as defined in the Code) and, (iii) after such three-month
or two-year period, as applicable, the Company shall repurchase the Mortgage Loan from the Trust at the Purchase Price but only if
the Mortgage Loan is in default or default is, in the judgment of the Company, reasonably imminent. If such defect would cause the
Mortgage Loan to be other than a “qualified mortgage” (as defined in the Code), then notwithstanding the previous
sentence or any provision in the definition of “Purchase Price,” the repurchase or substitution must occur within the
sooner of (i) 90 days from the date the defect was discovered or (ii) in the case of substitution, two years from the Closing
Date.


Such Substitute Mortgage Loan shall be an adjustable rate mortgage
loan with a first  Interest Rate Adjustment Date occurring on approximately the same date as the first Interest Rate
Adjustment Date for the Mortgage Loan being substituted for and adjustments monthly thereafter, based on the Index, and with the
same Monthly Payment Adjustment Terms as the Mortgage Loan being substituted for, mature no later than, and not more than two years
earlier than, have a principal balance and Loan-to-Value Ratio equal to or less than, and have a Pass-Through Rate on the date of
substitution equal to or no more than 1 percentage point greater than, and a Margin and Rate Ceiling equal to or greater than, the
Mortgage Loan being substituted for. If the aggregate of the principal balances of the Substitute Mortgage Loans substituted for a
Mortgage Loan is less than the Principal Balance of such Mortgage Loan, the Company shall pay the difference in cash, together with
unpaid accrued interest, if any, on the difference between the aggregate of the principal balances of the Substitute Mortgage Loans
and the Principal Balance of such Mortgage Loan during the calendar month in which the substitution occurs to the last day of such
month at a rate equal to the applicable Pass-Through Rate, to the Trustee for deposit into the Certificate Account, and such
payment by the Company shall be treated in the same manner as proceeds of the repurchase by the Company of a Mortgage Loan pursuant
to this Section 2.07. Furthermore, such Substitute Mortgage Loan shall otherwise have such characteristics so that the
representations and warranties of the Company set forth in Section 2.08 hereof would not have been incorrect had such Substitute
Mortgage Loan originally been a Mortgage Loan, and the Company shall be deemed to have made such representations and warranties as
to such Substitute Mortgage Loan. A Substitute Mortgage Loan may be substituted for a defective Mortgage Loan whether or not such
defective Mortgage Loan is itself a Substitute Mortgage Loan.  Notwithstanding anything herein to the contrary, each
Substitute Mortgage Loan shall be deemed to have the same Pass-Through Rate as the Mortgage Loan for which it was
substituted.


The Purchase Price for each purchased or repurchased Mortgage Loan
shall be deposited by the Company in the Certificate Account and, upon receipt by the Trustee of written notification of such
deposit signed by a Servicing Officer, the Trustee shall (or, if applicable, shall cause the Custodian to) release to the Company
the related Mortgage File and shall execute and deliver (or, in the event that the Mortgage Files are held in the name of the
Custodian, shall cause the Custodian to execute and deliver) on behalf of the Trust such instruments of transfer or assignment, in
each case without recourse, as shall be necessary to vest in the Company or its designee or assignee title to any Mortgage Loan
released pursuant hereto. In furtherance of the foregoing, if such Mortgage Loan is a MERS Loan and as a result of the repurchase
thereof such Mortgage Loan shall cease to be serviced by a servicer that is a member of MERS or if the Company or its assignee
shall so request, the Master Servicer shall cause MERS to execute and deliver an assignment of the Mortgage in recordable form from
MERS to the Company or its assignee and shall cause the Mortgage Loan to be removed from registration on the MERS® System in
accordance with MERS’ rules and procedures. The obligation of the Company to repurchase or substitute any Mortgage Loan as to
which such a defect in a constituent document exists shall constitute the sole remedy respecting such defect available to the Trust
or the Holders of the REMIC I Regular Interests or the Class R-1 Residual Interest.


Section
2.08.        Representations and Warranties of the Company Concerning the Mortgage Loans. With respect to the conveyance of the Mortgage Loans provided for in Section 2.04 herein, the
Company hereby represents and warrants to the Trust that as of the Cut-Off Date, unless otherwise indicated:


(i)                  The
information set forth in the Mortgage Loan Schedule was true and correct in all material respects at the date or dates respecting
which such information is furnished;


(ii)        As of the Closing Date, each Mortgage relating to a Mortgage Loan that is not
a Cooperative Loan is a valid and enforceable (subject to Section 2.08(xvi)) first lien on an unencumbered estate in fee simple or
(if the related Mortgage Loan is secured by the interest of the Mortgagor as a lessee under a ground lease) leasehold estate in the
related Mortgaged Property subject only to (a) liens for current real property taxes and special assessments; (b) covenants,
conditions and restrictions, rights of way, easements and other matters of public record as of the date of recording such Mortgage,
such exceptions appearing of record being acceptable to mortgage lending institutions generally or specifically reflected in the
appraisal obtained in connection with the origination of the Mortgage Loan; (c) exceptions set forth in the title insurance policy
relating to such Mortgage, such exceptions being acceptable to mortgage lending institutions generally; and (d) other matters to
which like properties are commonly subject which do not materially interfere with the benefits of the security intended to be
provided by the Mortgage;


(iii)       Immediately upon the transfer and assignment contemplated herein, the Trust shall
have good title to, and will be the sole legal owner of, each Mortgage Loan, free and clear of any encumbrance or lien (other than
any lien under this Agreement);


(iv)       As of the day prior to the Cut-Off Date, all payments due on each Mortgage Loan had
been made and no Mortgage Loan had been delinquent (i.e., was more than 30 days past due) more than once in the preceding 12 months
and any such delinquency lasted for no more than 30 days;


(v)        As of the Closing Date, there is no late assessment for delinquent taxes
outstanding against any Mortgaged Property;


(vi)       As of the Closing Date, there is no offset, defense or counterclaim to any Mortgage
Note, including the obligation of the Mortgagor to pay the unpaid principal or interest on such Mortgage Note except to the extent
that the Buydown Agreement for a Buydown Loan forgives certain indebtedness of a Mortgagor;


(vii)      As of the Closing Date, each Mortgaged Property is free of damage and in good repair,
ordinary wear and tear excepted;


(viii)      Each Mortgage Loan at the time it was made complied with all applicable local, state
and federal laws, including, without limitation, usury, equal credit opportunity, disclosure and recording laws, and predatory and
abusive lending laws applicable to the originating lender;


(ix)       Each Mortgage Loan was originated by a savings association, savings bank, credit
union, insurance company, or similar institution which is supervised and examined by a federal or state authority or by a mortgagee
approved by the FHA and will be serviced by an institution which meets the servicer eligibility requirements established by the
Company;


(x)        As of the Closing Date, each Mortgage Loan that is not a Cooperative Loan is
covered by an ALTA form or CLTA form of mortgagee title insurance policy or other form of policy of insurance which has been issued
by, and is the valid and binding obligation of, a title insurer which, as of the origination date of such Mortgage Loan, was
qualified to do business in the state in which the related Mortgaged Property is located. Such policy insures the originator of the
Mortgage Loan, its successors and assigns as to the first priority lien of the Mortgage in the original principal amount of the
Mortgage Loan subject to the exceptions set forth in such policy. Such policy is in full force and effect and inures to the benefit
of the Trust upon the consummation of the transactions contemplated by this Agreement and no claims have been made under such
policy, and no prior holder of the related Mortgage, including the Company, has done, by act or omission, anything which would
impair the coverage of such policy;


(xi)       Each Mortgage Loan with a Loan-to-Value Ratio as of its respective origination date
in excess of 80% was covered by a Primary Insurance Policy or an FHA insurance policy or a VA guaranty, and such policy or guaranty
is valid and remains in full force and effect;


(xii)      As of the Closing Date, all policies of insurance required by this Agreement or by a
Selling and Servicing Contract  have been validly issued and remain in full force and effect, including such policies covering
the Company, the Master Servicer or any Servicer;


(xiii)      As of the Closing Date, each insurer issuing a Primary Insurance Policy holds a rating
acceptable to the Rating Agencies;


(xiv)     Each Mortgage (exclusive of any riders thereto) was documented by appropriate Fannie
Mae/Freddie Mac mortgage instruments in effect at the time of origination, or other instruments approved by the
Company;


(xv)      As of the Closing Date, the Mortgaged Property securing each Mortgage relating to a
Mortgage Loan that is not a Cooperative Loan is improved with a one- to four-family dwelling unit, including units in a duplex,
triplex, fourplex, condominium project, townhouse, a planned unit development or a de minimis planned unit
development;


(xvi)     As of the Closing Date, each Mortgage and Mortgage Note is the legal, valid and binding
obligation of the maker thereof and is enforceable in accordance with its terms, except only as such enforcement may be limited by
laws affecting the enforcement of creditors’ rights generally and principles of equity;


(xvii)     As of the date of origination, as to Mortgaged Properties which are units in condominiums or
planned unit developments, all of such units met the applicable Underwriting Standards, are located in a condominium or planned
unit development projects which have received Fannie Mae or Freddie Mac approval, or are approvable by Fannie Mae or Freddie Mac or
have otherwise been approved by the Company;


(xviii)   
None of the Mortgage Loans are Buydown Loans;


(xix)     Based solely on representations of the Mortgagors obtained at the origination of the related
Mortgage Loans, approximately 92.62% (by Principal Balance) of the Mortgage Loans will be secured by owner occupied Mortgaged
Properties which are the primary residences of the related Mortgagors, approximately 6.42% (by Principal Balance) of the Mortgage
Loans will be secured by owner occupied Mortgaged Properties which were second or vacation homes of the Mortgagors and
approximately 0.96% (by Principal Balance) of the Mortgage Loans will be secured by Mortgaged Properties which were non-owner
occupied properties;


(xx)      Prior to origination or refinancing, an appraisal of each Mortgaged Property was made by
an appraiser on a form satisfactory to Fannie Mae or Freddie Mac;


(xxi)     The Mortgage Loans have been underwritten substantially in accordance with the applicable
Underwriting Standards;


(xxii)     All of the Mortgage Loans have due-on-sale clauses; however, the due on sale provisions may
not be exercised at the time of a transfer if prohibited by law or the terms of the related Mortgage Note;


(xxiii)   
The Company used no adverse selection procedures in selecting the Mortgage Loans from among the outstanding adjustable rate
conventional mortgage loans purchased by it which were available for inclusion in the Mortgage Pool and as to which the
representations and warranties in this Section 2.08 could be made;


(xxiv)   
With respect to any Mortgage Loan as to which an affidavit has been delivered to the Trustee certifying that the original Mortgage
Note is a Destroyed Mortgage Note, if such Mortgage Loan is subsequently in default, the enforcement of such Mortgage Loan or of
the related Mortgage by or on behalf of the Trust will not be materially adversely affected by the absence of the original Mortgage
Note (or portion thereof, as applicable);


(xxv)   
Based upon an appraisal of the Mortgaged Property securing each Mortgage Loan, approximately 99.06% (by Principal Balance) of the
Mortgage Loans had a current Loan-to-Value Ratio less than or equal to 80%, approximately 0.94% (by Principal Balance) of the
Mortgage Loans had a current Loan-to-Value Ratio greater than 80% but less than or equal to 90% and no Mortgage Loan had a current
Loan-to-Value Ratio greater than 90%;


(xxvi)   
Approximately 60.14% (by Principal Balance) of the Mortgage Loans were originated for the purpose of refinancing existing mortgage
debt, including cash-out refinancings; and approximately 39.86% (by Principal Balance) of the Mortgage Loans were originated for
the purpose of purchasing the Mortgaged Property;


(xxvii)   Not
less than approximately 30.34% (by Principal Balance) of the Mortgage Loans were originated under full documentation
programs;


(xxviii)  Each
Mortgage Loan constitutes a qualified mortgage under Section 860G(a)(3)(A) of the Code and Treasury Regulations Section
1.860G-2(a)(1); and


(xxix)    No Mortgage Loan is subject to the Home Ownership and Equity Protection Act of 1994 or Section 226.32 of Regulation Z, is a
“high-cost” loan or a “predatory” loan as defined under any state or local law or regulation applicable to
the originator of such Mortgage Loan or which would result in liability to the purchaser or assignee of such Mortgage Loan under
any predatory or abusive lending law, or, without limiting the generality of the foregoing, is a “covered” loan under
the laws of the states of California, Colorado or Ohio; and


(xxx)    No Mortgage Loan is a
High Cost Loan or Covered Loan (as such terms are defined in the Standard & Poor's LEVELS® Glossary in effect on the
Closing Date, which is now Version 5.6 Revised, Appendix E, applicable portions of which are attached hereto as Exhibit C) and no
Mortgage Loan originated on or after October 1, 2002 through March 6, 2003 is governed by the Georgia Fair Lending Act;


(xxxi)    With respect to each
Cooperative Loan, the Cooperative Stock that is pledged as security for the Cooperative Loan is held by a person as a
tenant-stockholder (as defined in Section 216 of the Code) in a cooperative housing corporation (as defined in Section 216 of the
Code); and


(xxxii)   Each Cooperative Loan is
secured by a valid, subsisting and enforceable (except as such enforcement may be limited by laws affecting the enforcement of
creditors’ rights generally and principles of equity) perfected first lien and security interest in the related Cooperative
Stock securing the related Mortgage Note, subject only to (a) liens of the Cooperative for unpaid assessments representing the
Mortgagor’s pro rata share of the Cooperative’s payments for its blanket mortgage, current and future real property
taxes, insurance premiums, maintenance fees and other assessments to which like collateral is commonly subject and (b) other
matters to which like collateral is commonly subject which do not materially interfere with the benefits of the security intended
to be provided by the Security Agreement.


It is understood and agreed that the representations and warranties
set forth in this Section 2.08 shall survive delivery of the respective Mortgage Files to the Trustee or the Custodian, as the case
may be, and shall continue throughout the term of this Agreement. Upon discovery by any of the Company, the Master Servicer, the
Trustee or the Custodian of a breach of any of the foregoing representations and warranties which materially and adversely affects
the value of the related Mortgage Loans or the interests of the Trust in the related Mortgage Loans, the Company, the Master
Servicer, the Trustee or the Custodian, as the case may be, discovering such breach shall give prompt written notice to the
others.  Any breach of the representation set forth in clause (xxix) or (xxx) of this Section 2.08 shall be deemed to
materially and adversely affect the value of the related Mortgage Loans or the interests of the Trust in the related Mortgage
Loans.  Within 90 days of its discovery or its receipt of notice of breach, the Company shall repurchase, subject to the
limitations set forth in the definition of “Purchase Price,” or substitute for the affected Mortgage Loan or Mortgage
Loans or any property acquired in respect thereof from the Trust, unless it has cured such breach in all material respects. 
After the end of the three-month period beginning on the “start-up day,” any such substitution shall be made only if
the Company provides to the Trustee an Opinion of Counsel addressed to the Trust and the Trustee reasonably satisfactory to the
Trustee that each Substitute Mortgage Loan will be a “qualified replacement mortgage” within the meaning of Section
860G(a)(4) of the Code. Such substitution shall be made in the manner and within the time limits set forth in Section 2.07. 
Any such repurchase by the Company shall be accomplished in the manner and at the Purchase Price, if applicable, but shall not be
subject to the time limits, set forth in Section 2.07.  It is understood and agreed that the obligation of the Company to
provide such substitution or to make such repurchase of any affected Mortgage Loan or Mortgage Loans or any property acquired in
respect thereof as to which a breach has occurred and is continuing shall constitute the sole remedy respecting such breach
available to the Holders of the REMIC I Regular Interests and the Class R-1 Residual Interest or the Trustee on behalf of the
Holders of the REMIC I Regular Interests and the Class R-1 Residual Interest.


Section
2.09.        Acknowledgment of Transfer of Mortgage Pool Assets. The Trustee hereby  acknowledges and accepts on behalf of the Trust the transfer and assignment to the Trust of the
Mortgage Pool Assets, but without having made the review required to be made within 45 days pursuant to Section 2.07, and declares
that as of the Closing Date it (or the Custodian on behalf of the Trustee) holds and shall hold any documents constituting a part
of the Mortgage Pool Assets, and the Mortgage Pool Assets, as Trustee in trust, upon the trust herein set forth, for the use and
benefit of all present and future Holders of the REMIC I Regular Interests and the Class R-1 Residual Interest.  In connection
therewith, as of the Closing Date, in exchange for the Mortgage Pool Assets, the Trust does hereby issue to the Company the REMIC I
Regular Interests and the Class R-1 Residual Interest.


Section
2.10.        Conveyance of REMIC II Assets; Security Interest.  Concurrently with the execution and delivery hereof, the Company does hereby irrevocably sell, transfer, assign, set
over and otherwise convey to the Trust, without recourse, all the Company’s right, title and interest in and to the REMIC II
Assets.  Pursuant to Section 3818 of the Statutory Trust Statute, the REMIC I Regular Interests shall not be cancelled and
shall be held as treasury interests owned by the Trust.  The Trustee acknowledges that the REMIC II Assets are held by it as
Trustee of the Trust for the benefit of the holders of the Certificates.  It is the express intent of the parties hereto that
the conveyance of the REMIC II Assets to the Trust by the Company as provided in this Section 2.10 be, and be construed as, an
absolute sale of the REMIC II Assets.  It is, further, not the intention of the parties that such conveyance be deemed the
grant of a security interest in the REMIC II Assets by the Company to the Trust to secure a debt or other obligation of the
Company.  However, in the event that, notwithstanding the intent of the parties, the REMIC II Assets are held to be the
property of the Company, or if for any other reason this Agreement is held or deemed to create a security interest in the REMIC II
Assets, then:


(a)        this Agreement shall
constitute a security agreement;


(b)        the conveyance provided
for in this Section 2.10 shall be deemed to be a grant by the Company to the Trust of, and the Company hereby grants to the Trust,
to secure all of the Company’s obligations hereunder, a security interest in all of the Company’s right, title and
interest, whether now owned or hereafter acquired, in and to:


(I)       
The REMIC I Regular Interests, including without limitation all rights represented thereby in and to the Mortgage Pool Assets and
the proceeds thereof;


(II)       All
accounts, chattel paper, deposit accounts, documents, general intangibles, goods, instruments, investment property,
letter-of-credit rights, letters of credit, money, and oil, gas, and other minerals, consisting of, arising from, or relating to,
any of the foregoing; and


(III)      All
proceeds of the foregoing.


The Company shall file such financing statements, and the Company and
the Trustee acting on behalf of the Trust at the direction of the Company shall, to the extent consistent with this Agreement, take
such other actions as may be necessary to ensure that, if this Agreement were found to create a security interest in the REMIC II
Assets, such security interest would be a perfected security interest of first priority under applicable law and will be maintained
as such throughout the term of this Agreement. In connection herewith, the Trust shall have all of the rights and remedies of a
secured party and creditor under the Uniform Commercial Code as in force in the relevant jurisdiction.


In the event that a pleading is filed in a court of competent
jurisdiction asserting that this Agreement creates a security interest in the REMIC II Assets, the Trustee on behalf of the Trust
shall take actual possession of the REMIC II Assets or, at the Company's option, the Trustee on behalf of the Trust shall be
provided an Opinion of Counsel addressed to the Trust and the Trustee reasonably satisfactory to the Trustee to the effect that
such security interest is a perfected security interest of first priority while the REMIC II Assets are in the possession of the
Company or its affiliates.


Section 2.11.        REMIC Election for REMIC II.


The Tax Matters Person shall, on behalf of REMIC II, elect to treat
REMIC II as a REMIC within the meaning of Section 860D of the Code and, if necessary, under applicable state laws. Such election
shall be included in the Form 1066 and any appropriate state return to be filed on behalf of REMIC II for its first taxable
year.


The Closing Date is hereby designated as the “startup day”
of REMIC II within the meaning of Section 860G(a)(9) of the Code.


The regular interests (as set forth in the table contained in the
Preliminary Statement hereto) relating to REMIC II are hereby designated as “regular interests” in REMIC II for
purposes of Section 860G(a)(1) of the Code. The Class R-2 Residual Interest is hereby designated as the sole class of
“residual interest” in REMIC II for purposes of Section 860G(a)(2) of the Code. The REMIC II Regular Interests and the
Class R-2 Residual Interest shall together be deemed to be a separate series of beneficial interests in the assets of the Trust
consisting of the REMIC II Assets pursuant to Section 3806(b)(2) of the Statutory Trust Statute.


The parties intend that the affairs of REMIC II shall constitute, and
that the affairs of REMIC II shall be conducted so as to qualify it as, a REMIC. In furtherance of such intention, the Tax Matters
Person shall, on behalf of REMIC II: (a) prepare and file, or cause to be prepared and filed, a federal tax return using a calendar
year as the taxable year for REMIC II when and as required by the REMIC provisions and other applicable federal income tax laws;
(b) make an election, on behalf of REMIC II, to be treated as a REMIC on the federal tax return of REMIC II for its first taxable
year, in accordance with the REMIC provisions; (c) prepare and forward, or cause to be prepared and forwarded, to the
Certificateholders and the Holders of the Class R-2 Residual Interest all information reports as and when required to be provided
to them in accordance with the REMIC provisions (which information reports, in the case of each Class of Class A Certificates,
shall reflect the respective amounts of interest that are to be treated as having been (i) received by such Class from REMIC II and
(ii) received by such Class from the Class X Certificates outside of REMIC II pursuant to Section 2.16, and which information
reports, in the case of the Class X Certificates, shall reflect the respective amounts of interest that are to be treated as having
been (i) received by such Class from REMIC II and (ii) paid by such Class to the Class A Certificates outside of REMIC II pursuant
to Section 2.16); (d) conduct the affairs of REMIC II at all times that any of the Certificates are outstanding so as to maintain
the status of REMIC II as a REMIC under the REMIC provisions; (e) not knowingly or intentionally take any action or omit to take
any action that would cause the termination of the REMIC status of REMIC II; and (f) pay the amount of any federal prohibited
transaction penalty taxes imposed on REMIC II when and as the same shall be due and payable (but such obligation shall not prevent
the Company or any other appropriate person from contesting any such tax in appropriate proceedings and shall not prevent the
Company from withholding payment of such tax, if permitted by law, pending the outcome of such proceedings); provided, that the
Company shall be entitled to be indemnified from REMIC II for any such prohibited transaction penalty taxes if the Company’s
failure to exercise reasonable care was not the primary cause of the imposition of such prohibited transaction penalty
taxes.


In the event that any tax is imposed on “prohibited
transactions” of REMIC II as defined in Section 860F of the Code and not paid by the Company pursuant to clause (f) of the
preceding paragraph, such tax shall be charged against amounts otherwise distributable to the Holders of the Class R-2 Residual
Interest. Notwithstanding anything to the contrary contained herein, the Company is hereby authorized to retain from amounts
otherwise distributable to the Holders of the Class R-2 Residual Interest on any Distribution Date sufficient funds to reimburse
the Company for the payment of such tax (to the extent that the Company has not been previously reimbursed therefor).


Section 2.12.        Acknowledgement of Transfer of REMIC II Assets; Authentication of
Certificates. The Trustee hereby acknowledges and accepts on behalf of
the Trust the assignment to the Trust of the REMIC II Assets and declares that as of the Closing Date it holds and shall hold any
documents constituting a part of the REMIC II Assets, and the REMIC II Assets, as Trustee in trust, upon the trust herein set
forth, for the use and benefit of all present and future Holders of the Certificates (other than the Class R and Class Y
Certificates) and the Class R-2 Residual Interest.  In connection therewith, as of the Closing Date, in exchange for the REMIC
II Assets, the Trustee on behalf of the Trust shall cause to be authenticated and delivered, upon and pursuant to the order of the
Company, the Certificates in Authorized Denominations.


Section 2.13.        Legal Title.
Legal title to all assets of the Trust shall be vested at all times in the Trust as a separate legal entity.


Section 2.14.        Compliance with ERISA Requirements. For purposes of ensuring compliance with the requirements of the “underwriter’s exemption”
(U.S. Department of Labor Prohibited Transaction Exemption 2002-41, 67 Fed. Reg. 54487 (Aug. 22, 2002), as amended), issued under
ERISA, and for the avoidance of any doubt as to the applicability of other provisions of this Agreement, to the fullest extent
permitted by applicable law and except as contemplated by this Agreement, (1) the Trust shall not be a party to any merger,
consolidation or reorganization, or liquidate or sell its assets and (2) so long as any Certificates are outstanding, none of the
Company, the Trustee or the Delaware Trustee shall institute against the Trust, or join in any institution against the Trust of,
any bankruptcy or insolvency proceedings under any federal or state bankruptcy, insolvency or similar law.


Section 2.15.        Additional Representation of the Company Concerning the Mortgage
Loans. The Company hereby represents and warrants to the Trust that it
does not intend for the Mortgage Pool to include any Mortgage Loan that is a “high-cost home loan” as defined under the
New Jersey Home Ownership Security Act of 2002 or the New Mexico Home Loan Protection Act. Based on the foregoing representation
and warranty and on the Company’s obligation, pursuant to Section 2.08, to repurchase or substitute for the affected Mortgage
Loan in the event of a breach of the representation set forth in clause (xxix) of Section 2.08, the other parties hereto agree and
understand that it is not intended for the Mortgage Pool to include any Mortgage Loan that is a “high-cost home loan”
as defined under the New Jersey Home Ownership Security Act of 2002 or the New Mexico Home Loan Protection Act.


Section 2.16.        Distributions to Certain Class A Certificates Outside of REMIC
II. For tax purposes, for any Distribution Date for which a
distribution of a Carryover Shortfall Payment has been made to any Class of Class A Certificates (no such distributions shall be
made to the Class A-3 Certificates) pursuant to the second sentence of Section 4.04(a), such Class shall be treated as (i) having
received the portion of the REMIC II Available Distribution Amount distributed to the Corresponding Class of REMIC II Regular
Interests for such Distribution Date and (ii) having received from the Class X Certificates, outside of REMIC II, the Carryover
Shortfall Payment for such Class.  For tax purposes, for any such Distribution Date, the Class X Certificates shall be treated
as (i) having received the portion of the REMIC II Available Distribution Amount distributed to the Class X-L Regular Interest
for such Distribution Date and (ii) having paid to each such Class of Class A Certificates (other than the Class A-3
Certificates), outside of REMIC II, the Carryover Shortfall Payment for such Class.


ARTICLE III



Administration and Servicing of Mortgage Loans


Section
3.01.        The Company to Act as Master Servicer.  The Company shall act as Master Servicer to service and administer the Mortgage Loans on behalf of the Trust in
accordance with the terms hereof, consistent with prudent mortgage loan servicing practices and (unless inconsistent with prudent
mortgage loan servicing practices) in the same manner in which, and with the same care, skill, prudence and diligence with which,
it services and administers similar mortgage loans for other portfolios, and shall have full power and authority to do or cause to
be done any and all things in connection with such servicing and administration which a prudent servicer of mortgage loans would do
under similar circumstances, including, without limitation, the power and authority to bring actions and defend the Mortgage Pool
Assets on behalf of the Trust in order to enforce the terms of the Mortgage Notes.  The Master Servicer may perform its master
servicing responsibilities through agents or independent contractors, but shall not thereby be released from any of its
responsibilities hereunder and the Master Servicer shall diligently pursue all of its rights against such agents or independent
contractors.


The Master Servicer shall make reasonable efforts to collect or cause
to be collected all payments called for under the terms and provisions of the Mortgage Loans and shall, to the extent such
procedures shall be consistent with this Agreement and the terms and provisions of any Primary Insurance Policy, any FHA insurance
policy or VA guaranty, any hazard insurance policy, and federal flood insurance, cause to be followed such collection procedures as
are followed with respect to mortgage loans comparable to the Mortgage Loans and held in portfolios of responsible mortgage lenders
in the local areas where each Mortgaged Property is located. The Master Servicer shall enforce “due-on-sale” clauses
with respect to the related Mortgage Loans, to the extent permitted by law, subject to the provisions set forth in Section
3.08.


Consistent with the foregoing, the Master Servicer may, in accordance
with prudent mortgage loan servicing practices, (i) waive or cause to be waived any assumption fee or late payment charge in
connection with the prepayment of any Mortgage Loan and (ii) only upon determining that the coverage of any applicable insurance
policy or guaranty related to a Mortgage Loan will not be materially adversely affected, arrange a schedule, running for no more
than 180 days after the first delinquent Due Date, for payment of any delinquent installment on any Mortgage Note or for the
liquidation of delinquent items. Subject to the fourth sentence of this paragraph, the Master Servicer shall have the right, but
not the obligation, to purchase any Mortgage Loan delinquent 90 consecutive days or more for an amount equal to its Purchase Price;
provided, however, that the aggregate Purchase Price of Mortgage Loans so purchased pursuant to this sentence shall not
exceed one-half of one percent (0.50%) of the aggregate Principal Balance, as of the Cut-Off Date, of all Mortgage Loans. 
Subject to the fourth sentence of this paragraph, the Master Servicer shall also have the right, but not the obligation, to
purchase, for an amount equal to its Purchase Price, any Mortgage Loan delinquent 90 consecutive days or more, for the purpose of
requiring the Person who sold such Mortgage Loan to the Company to repurchase such Mortgage Loan based on a breach of a
representation or warranty made by such Person in connection with the Company’s purchase or acquisition of such Mortgage
Loan.  Notwithstanding the immediately preceding two sentences, the Master Servicer’s right to purchase any Mortgage
Loan pursuant to either of such preceding sentences shall be subject to the following additional conditions: (x) if the date on
which the Mortgage Loan first became 90-day delinquent (the “Initial Delinquency Date”) occurred during the
first two calendar months of a calendar quarter, the Master Servicer may exercise the purchase right during the period commencing
on the Initial Delinquency Date and ending on the last Master Servicer Business Day of such calendar quarter, (y) if the Initial
Delinquency Date occurred during the third calendar month of a calendar quarter, the Master Servicer may exercise the purchase
right during the period commencing on the first day of the immediately succeeding calendar quarter and ending on the last Master
Servicer Business Day of such succeeding calendar quarter and (z) if the Master Servicer does not exercise the purchase right with
respect to a Mortgage Loan during the period specified in clause (x) or (y), as applicable, such Mortgage Loan shall thereafter
again become eligible for purchase pursuant to the preceding two sentences only after the Mortgage Loan ceases to be 90-day
delinquent and thereafter becomes 90-day delinquent again.  For purposes of this paragraph, a Mortgage Loan is considered
delinquent for 90 consecutive days if a Monthly Payment is not received by the first day of the third month following the month
during which such payment was due.


Consistent with the terms of this Section 3.01, the Master Servicer
may waive, modify or vary any term of any Mortgage Loan or consent to the postponement of strict compliance with any such term or
in any manner grant indulgence to any Mortgagor if it has determined, exercising its good faith business judgment in the same
manner as it would if it were the owner of the related Mortgage Loan, that the security for, and the timely and full collectability
of, such Mortgage Loan would not be adversely affected by such waiver, modification, postponement or indulgence; provided,
however, that (unless the Mortgagor is in default with respect to the Mortgage Loan or in the reasonable judgment of the Master
Servicer such default is imminent) the Master Servicer shall not permit any modification with respect to any Mortgage Loan that
would (i) change the applicable Mortgage Interest Rate, defer or forgive the payment of any principal or interest, reduce the
outstanding principal balance (except for actual payments of principal) or extend the final maturity date with respect to such
Mortgage Loan, or (ii) be inconsistent with the terms of any applicable Primary Insurance Policy, FHA insurance policy, VA
guaranty, hazard insurance policy or federal flood insurance policy. Notwithstanding the foregoing, the Master Servicer shall not
permit any modification with respect to any Mortgage Loan that would both constitute a sale or exchange of such Mortgage Loan
within the meaning of Section 1001 of the Code (including any proposed, temporary or final regulations promulgated thereunder)
(other than in connection with a proposed conveyance or assumption of such Mortgage Loan that is treated as a Principal Prepayment
or in a default situation) and cause any REMIC to fail to qualify as such under the Code. The Master Servicer shall be entitled to
approve a request from a Mortgagor for a partial release of the related Mortgaged Property, the granting of an easement thereon in
favor of another Person, any alteration or demolition of the related Mortgaged Property or other similar matters if it has
determined, exercising its good faith business judgment in the same manner as it would if it were the owner of the related Mortgage
Loan, that the security for, and the timely and full collectability of, such Mortgage Loan would not be adversely affected thereby
and that REMIC I and REMIC II would not fail to continue to qualify as REMICs under the Code as a result thereof and that no tax on
“prohibited transactions” or “contributions” after the startup day would be imposed on any REMIC as a
result thereof.


The Master Servicer is hereby authorized and empowered by the Trust to
execute and deliver or cause to be executed and delivered on behalf of the Holders of the REMIC I Regular Interests and the Class
R-1 Residual Interest, and the Trust or any of them, any and all instruments of satisfaction or cancellation, or of partial or full
release, discharge or modification, assignments of Mortgages and endorsements of Mortgage Notes in connection with refinancings (in
jurisdictions where such assignments are the customary and usual standard of practice of mortgage lenders) and all other comparable
instruments, with respect to the Mortgage Loans and with respect to the Mortgaged Properties. The Master Servicer is hereby further
authorized and empowered by the Trust to execute and deliver or cause to be executed and delivered on behalf of the Holders of the
REMIC I Regular Interests and the Class R-1 Residual Interest and the Trust, or any of them, such instruments of assignment or
other comparable instruments as the Master Servicer shall, in its sole judgment, deem appropriate in order to register any Mortgage
Loan on the MERS® System or to cause the removal of any Mortgage Loan from registration thereon. Any expenses incurred in
connection with the actions described in the preceding sentence shall be borne by the Master Servicer with no right of
reimbursement; provided, however, that any such expenses incurred as a result of any termination by MERS of the MERS®
System shall be reimbursable to the Master Servicer.  The Trustee on behalf of the Trust shall execute and furnish to the
Master Servicer, at the Master Servicer’s direction, any powers of attorney and other documents prepared by the Master
Servicer and determined by the Master Servicer to be necessary or appropriate to enable the Master Servicer to carry out its
supervisory, servicing and administrative duties under this Agreement.


The Master Servicer and each Servicer shall obtain (to the extent
generally commercially available) and maintain fidelity bond and errors and omissions coverage acceptable to Fannie Mae or Freddie
Mac with respect to their respective obligations under this Agreement and the applicable Selling and Servicing Contract,
respectively.  The Master Servicer or each Servicer, as applicable, shall establish escrow accounts for, or pay when due (by
means of an advance), any tax liens in connection with the Mortgaged Properties that are not paid by the Mortgagors when due to the
extent that any such payment would not constitute a Nonrecoverable Advance when made.


In connection with the servicing and administering of each Mortgage
Loan, the Master Servicer and any affiliate of the Master Servicer (i) may perform services such as appraisals, default management
and (in the case of affiliates only) brokerage services that are not customarily provided by servicers of mortgage loans, and shall
be entitled to reasonable compensation therefor and (ii) may, at its own discretion and on behalf of the Trust, obtain credit
information in the form of a “credit score” from a credit repository.


Section
3.02.        Custodial Accounts and Buydown Fund Accounts. The Master Servicer shall cause to be established and maintained by each Servicer under the Master Servicer’s
supervision the Custodial Account for P&I, Buydown Fund Accounts (if any) and special Custodial Account for Reserves and shall
deposit or cause to be deposited therein daily the following amounts received or advanced by the Servicer with respect to the
Mortgage Loans:


(i)         all scheduled payments of principal;


(ii)        all scheduled payments of interest, net of the Servicing Fees due the
applicable Servicers;


(iii)       all Curtailments and Payoffs; and


(iv)       all Insurance Proceeds, Liquidation Proceeds, Excess Liquidation Proceeds and
Subsequent Recoveries;


provided, however, that (x) proceeds received with respect to individual
Mortgage Loans from any title, hazard, or FHA insurance policy, VA guaranty, Primary Insurance Policy or other insurance policy
(other than any Special Primary Insurance Policy) covering such Mortgage Loans, if required for the restoration or repair of the
related Mortgaged Property, may be deposited either in the Custodial Account for Reserves or the Custodial Account for P&I and
(y) such proceeds (other than proceeds from any Special Primary Insurance Policy), if not required for the restoration or repair of
the related Mortgaged Property, and if not released to the Mortgagor in accordance with prudent mortgage loan servicing practices,
shall be deposited in the Custodial Account for P&I, and shall be applied to the balances of the related Mortgage Loans as
payments of interest and principal.


The Master Servicer is hereby authorized to make withdrawals from and
to issue drafts against the Custodial Accounts for P&I and the Custodial Accounts for Reserves for the purposes required or
permitted by this Agreement. Each Custodial Account for P&I and each Custodial Account for Reserves shall bear a designation
clearly showing the respective interests of the applicable Servicer, as trustee, and of the Master Servicer, in substantially one
of the following forms:


(a)       
With respect to the Custodial Account for P&I: (i) [Servicer’s Name], as agent, trustee and/or bailee of principal and
interest custodial account for Washington Mutual Mortgage Securities Corp., its successors and assigns, for various owners of
interests in Washington Mutual Mortgage Securities Corp. mortgage-backed pools or (ii) [Servicer’s Name] in trust for
Washington Mutual Mortgage Securities Corp.;


(b)       
With respect to the Custodial Account for Reserves: (i) [Servicer’s Name], as agent, trustee and/or bailee of taxes and
insurance custodial account for Washington Mutual Mortgage Securities Corp., its successors and assigns for various mortgagors
and/or various owners of interests in Washington Mutual Mortgage Securities Corp. mortgage-backed pools or (ii) [Servicer’s
Name] in trust for Washington Mutual Mortgage Securities Corp. and various Mortgagors.


The Master Servicer hereby undertakes to assure remittance to the
Certificate Account of all amounts relating to the Mortgage Loans that have been collected by any Servicer and are due to the
Certificate Account pursuant to Section 4.01 of this Agreement.


Funds held in the Custodial Account for P&I and the Custodial
Account for Reserves may, at the Master Servicer’s option, be invested in (i) one or more Eligible Investments which shall in
no event mature later than the Business Day prior to the related Withdrawal Date (except if such Eligible Investments are
obligations of the Trustee, such Eligible Investments may mature on the Withdrawal Date), or (ii) such other instruments as shall
be required to maintain the Ratings.


Section
3.03.        The Investment Account; Eligible Investments. (a)    Not later than the Withdrawal Date, the Master Servicer shall withdraw or direct the withdrawal of
funds in the Custodial Accounts for P&I, for deposit in the Investment Account, in an amount representing:


(i)                 
Scheduled installments of principal and interest on the Mortgage Loans received or advanced by the applicable Servicers which were
due on the related Due Date, net of the Servicing Fees due the applicable Servicers and less any amounts to be withdrawn later by
the applicable Servicers from the applicable Buydown Fund Accounts;


(ii)                Payoffs and the
proceeds of other types of liquidations of the Mortgage Loans received by the applicable Servicer for such Mortgage Loans during
the applicable Payoff Period, with interest to the date of Payoff or liquidation less any amounts to be withdrawn later by the
applicable Servicers from the applicable Buydown Fund Accounts; and


(iii)               Curtailments received
by the applicable Servicers in the Prior Period.


At its option, the Master Servicer may invest funds withdrawn from the
Custodial Accounts for P&I, as well as any Buydown Funds, Insurance Proceeds and Liquidation Proceeds previously received by
the Master Servicer (including amounts paid by the Company in respect of any Purchase Obligation or its substitution obligations
set forth in Section 2.07 or Section 2.08 or in connection with the exercise of the option to terminate this Agreement pursuant to
Section 9.01) for its own account and at its own risk, during any period prior to their deposit in the Certificate Account. Such
funds, as well as any funds which were withdrawn from the Custodial Accounts for P&I on or before the Withdrawal Date, but not
yet deposited into the Certificate Account, shall immediately be deposited by the Master Servicer with the Investment Depository in
an Investment Account in the name of the Master Servicer and the Trust for investment only as set forth in this Section 3.03. The
Master Servicer shall bear any and all losses incurred on any investments made with such funds and shall be entitled to retain all
gains realized on such investments as additional servicing compensation. Not later than the Business Day prior to the Distribution
Date, the Master Servicer shall deposit such funds, net of any gains (except Payoff Earnings) earned thereon, in the Certificate
Account.


(b)        Funds held in the
Investment Account shall be invested in (i) one or more Eligible Investments which shall in no event mature later than the Business
Day prior to the related Distribution Date (except if such Eligible Investments are obligations of the Trustee, such Eligible
Investments may mature on the Distribution Date), or (ii) such other instruments as shall be required to maintain the
Ratings.


Section 3.04.        The Certificate Account.


(a)        On or prior to the
Closing Date, the Trustee shall establish the Certificate Account, which shall be entitled “Washington Mutual Mortgage
Securities Corp. Certificate Account under the Pooling and Servicing Agreement, dated as of January 1, 2005, among Washington
Mutual Mortgage Securities Corp., as Depositor and Master Servicer, Deutsche Bank National Trust Company, as the Trustee, and
Deutsche Bank Trust Company Delaware, as the Delaware Trustee, for the benefit of WaMu Mortgage Pass-Through Certificates Series
2005-AR1 Trust created pursuant thereto”.  Promptly after the Closing Date, the Trustee shall communicate to the Master
Servicer the account number and wiring instructions for the Certificate Account.


Not later than the Business Day prior to the related Distribution
Date, the Master Servicer shall direct the Investment Depository to deposit into the Certificate Account the amounts previously
deposited into the Investment Account (which may include a deposit of Eligible Investments) to which the Holders of the REMIC I
Regular Interests and the Class R-1 Residual Interest are entitled or which are necessary for payment of any Special Primary
Insurance Premiums. In addition, not later than the Business Day prior to the Distribution Date, the Master Servicer shall deposit
into the Certificate Account any Monthly P&I Advances or other payments required to be made by the Master Servicer pursuant to
Section 4.02 of this Agreement and any Insurance Proceeds or Liquidation Proceeds (including amounts paid by the Company in respect
of any Purchase Obligation) not previously deposited in the Custodial Accounts for P&I or the Investment Account, and any
amounts paid by the Master Servicer in connection with the exercise of its option to terminate this Agreement pursuant to Section
9.01 or any other purchase of Mortgage Loans permitted by this Agreement.


(b)        Funds held in the
Certificate Account shall be invested at the written direction of the Master Servicer in (i) one or more Eligible Investments which
shall in no event mature later than the Business Day prior to the related Distribution Date (except if such Eligible Investments
are obligations of the Trustee, such Eligible Investments may mature on the Distribution Date), or (ii) such other instruments as
shall be required to maintain the Ratings.  The Master Servicer shall be entitled to receive any gains earned on such Eligible
Investments and shall bear any losses suffered in connection therewith.  If the Trustee has not received such written
investment directions from the Master Servicer, the Trustee shall not invest funds held in the Certificate Account.  The
Trustee shall have no liability for any losses on investments of funds held in the Certificate Account.


In the event the Trustee makes such investments, the parties
acknowledge that the Trustee or its affiliates may receive additional compensation (not payable pursuant to this Agreement) that
could be deemed to be in the Trustee's economic self-interest for (i) serving as investment adviser, administrator, shareholder,
servicing agent, custodian or sub-custodian with respect to certain of the Eligible Investments, (ii) using affiliates to effect
transactions in certain Eligible Investments and (iii) effecting transactions in certain Eligible Investments.


Section 3.05.        Permitted Withdrawals from the Certificate Account, the Investment
Account, Custodial Accounts for P&I and Custodial Accounts
for Reserves and of Buydown Funds from the Buydown Fund
Accounts.


(a)        The
Master Servicer is authorized to make withdrawals (or, in the case of the Certificate Account, to direct the Trustee to make
withdrawals), from time to time, from the Investment Account, the Certificate Account, the Custodial Accounts for P&I
or the Custodial Accounts for Reserves established by the
Servicers of amounts deposited therein in respect of the Certificates (and, to the extent applicable, to make deposits of the
amounts withdrawn), as follows:


(i)                  To
reimburse itself or the applicable Servicer for Monthly P&I Advances made pursuant to Section 4.02 or a Selling and Servicing
Contract, such right to reimbursement pursuant to this paragraph (i) being limited to amounts received on particular Mortgage Loans
(including, for this purpose, Insurance Proceeds and Liquidation Proceeds) which represent late recoveries of principal and/or
interest respecting which any such Monthly P&I Advance was made;


(ii)                To reimburse
itself or the applicable Servicer for amounts expended by or for the account of the Master Servicer pursuant to Section 3.09 or
amounts expended by such Servicer pursuant to the Selling and Servicing Contracts in connection with the restoration of property
damaged by an Uninsured Cause or in connection with the liquidation of a Mortgage Loan;


(iii)               To pay to itself, with
respect to the related Mortgage Loans, the Master Servicing Fee (net of Compensating Interest reduced by Payoff Earnings and Payoff
Interest) as to which no prior withdrawals from funds deposited by the Master Servicer have been made;


(iv)              To reimburse itself or the applicable Servicer for advances made with respect to related Mortgage Loans
(except for Mortgage Loans purchased pursuant to a Purchase Obligation or pursuant to the second or third sentence of the third
paragraph of Section 3.01) for (A) amounts advance with
respect to payments of taxes referred to in the last sentence of the sixth paragraph of Section 3.01 (to the extent that such
amounts have not otherwise been recovered by the Master Servicer or the Servicer, as applicable), (B) amounts incurred in
maintaining any insurance described in Section 3.07 and (C) for amounts which the
Master Servicer has determined to be Nonrecoverable Advances;


(v)                To pay to itself
reinvestment earnings deposited or earned in the Investment Account and the Certificate Account to which it is entitled and to
reimburse itself for expenses incurred by and reimbursable to it pursuant to Section 6.03;


(vi)              To deposit to the Investment
Account amounts in the Certificate Account not required to be on deposit therein at the time of such withdrawal;


(vii)             To deposit in the Certificate
Account, not later than the Business Day prior to the related Distribution Date, the amounts in the Investment Account specified in
Section 3.04(a);


(viii)           To pay on behalf of the Trustee any Special
Primary Insurance Premium payable by the Trustee pursuant to Section 4.04(a); provided, the Master Servicer shall give
written notice thereof to the Trustee prior to noon New York City time two Business Days prior to the applicable Distribution Date;
and


after
making or providing for the above withdrawals


(ix)              To clear and terminate the
Investment Account and the Certificate Account following termination of this Agreement pursuant to Section 9.01.


Since, in connection with withdrawals pursuant to paragraphs (i) and
(ii), the Master Servicer’s entitlement thereto is limited to collections or other recoveries on the related Mortgage Loan,
the Master Servicer or the applicable Servicer shall keep and maintain, separate accounting for each Mortgage Loan, for the purpose
of justifying any such withdrawals.


(b)        The Master Servicer or
the applicable Servicer, if such Servicer holds and maintains a Buydown Fund Account, is authorized to make withdrawals, from time
to time, of Buydown Funds from the Buydown Fund Account or Custodial Account for P&I established by any Servicer under its
supervision (and, to the extent applicable, to make deposits of the amounts withdrawn), as follows:


(i)         To deposit each month in the Investment Account the amount necessary to
supplement payments received on Buydown Loans;


(ii)        In the event of a Payoff of any Mortgage Loan having a related Buydown Fund,
to apply amounts remaining in Buydown Fund Accounts to reduce the required amount of such principal Payoff (or, if the Mortgagor
has made a Payoff, to refund such remaining Buydown Fund amounts to the Person entitled thereto);


(iii)       In the event of foreclosure or liquidation of any Mortgage Loan having a Buydown
Fund, to deposit remaining Buydown Fund amounts in the Investment Account as Liquidation Proceeds; and


(iv)       To clear and terminate the portion of any account representing Buydown Funds
following termination of this Agreement pursuant to Section 9.01;


(c)        The Trustee is
authorized to make withdrawals from time to time from the Certificate Account to reimburse itself for advances it has made as
successor Master Servicer pursuant to Section 7.01(a) hereof that it has determined to be Nonrecoverable Advances.


(d)        Each Servicer is
authorized to make withdrawals, from time to time, from the related Custodial Account for P&I, (i) to pay to itself, with
respect to the related Mortgage Loans, the Servicing Fee and (ii) to reimburse itself for expenses to the same extent that the
Master Servicer is authorized to make withdrawals to reimburse the Servicer for expenses pursuant to clauses (i), (ii) and (iv) of
Section 3.05(a), in the case of each of clause (d)(i) and (d)(ii), to the extent no prior withdrawals of such amounts have been
made by the Servicer or the Master Servicer.


Section
3.06.        Maintenance of Primary Insurance Policies; Collections Thereunder. The Master Servicer shall use commercially reasonable efforts to keep, or to cause the Servicers to keep,
in full force and effect each Primary Insurance Policy (except any Special Primary Insurance Policy) required with respect to a
Mortgage Loan until no longer required, and the Master Servicer shall use commercially reasonable efforts to keep in full force and
effect each Special Primary Insurance Policy, if any. Notwithstanding the foregoing, the Master Servicer shall have no obligation
to maintain any Primary Insurance Policy for a Mortgage Loan for which the outstanding Principal Balance thereof at any time
subsequent to origination was 80% or less of the Appraised Value of the related Mortgaged Property, unless required by applicable
law.


Unless required by applicable law, the Master Servicer shall not
cancel or refuse to renew, or allow any Servicer under its supervision to cancel or refuse to renew, any Primary Insurance Policy
in effect at the date of the initial issuance of the Certificates that is required to be kept in force hereunder; provided,
however, that neither the Master Servicer nor any Servicer shall advance funds for the payment of any premium due under (i) any
Primary Insurance Policy (other than a Special Primary Insurance Policy) if it shall determine that such an advance would be a
Nonrecoverable Advance or (ii) any Special Primary Insurance Policy.


Section
3.07.        Maintenance of Hazard Insurance. The
Master Servicer shall cause to be maintained for each Mortgage Loan (other than a Cooperative Loan) fire insurance with extended
coverage in an amount which is not less than the original principal balance of such Mortgage Loan, except in cases approved by the
Master Servicer in which such amount exceeds the value of the improvements to the Mortgaged Property. The Master Servicer shall
also require fire insurance with extended coverage in a comparable amount on property acquired upon foreclosure, or deed in lieu of
foreclosure, of any Mortgage Loan (other than a Cooperative Loan). Any amounts collected under any such policies (other than
amounts to be applied to the restoration or repair of the related Mortgaged Property) shall be deposited into the Custodial Account
for P&I, subject to withdrawal pursuant to the applicable Selling and Servicing Contract and pursuant to Section 3.03 and
Section 3.05. Any unreimbursed costs incurred in maintaining any insurance described in this Section 3.07 shall be recoverable as
an advance by the Master Servicer or the applicable Servicer from the related Custodial Account for P&I, the Investment Account
or the Certificate Account. Such insurance shall be with insurers approved by the Master Servicer and Fannie Mae or Freddie Mac.
Other additional insurance may be required of a Mortgagor, in addition to that required pursuant to such applicable laws and
regulations as shall at any time be in force and as shall require such additional insurance. Where any part of any improvement to
the Mortgaged Property (other than a Mortgaged Property secured by a Cooperative Loan) is located in a federally designated special
flood hazard area and in a community which participates in the National Flood Insurance Program at the time of origination of the
related Mortgage Loan, the Master Servicer shall cause flood insurance to be provided. The hazard insurance coverage required by
this Section 3.07 may be met with blanket policies providing protection equivalent to individual policies otherwise required. 
The Master Servicer or the applicable Servicer shall be responsible for paying any deductible amount on any such blanket
policy.  The Master Servicer agrees to present, or cause to be presented, on behalf of and for the benefit of the Trust,
claims under the hazard insurance policy respecting any Mortgage Loan, and in this regard to take such reasonable actions as shall
be necessary to permit recovery under such policy.


Section
3.08.        Enforcement of Due-on-Sale Clauses; Assumption Agreements. When any Mortgaged Property is about to be conveyed by the Mortgagor, the Master Servicer shall, to the extent
it has knowledge of such prospective conveyance and prior to the time of the consummation of such conveyance, exercise on behalf of
the Trust the Trust’s rights to accelerate the maturity of such Mortgage Loan, to the extent that such acceleration is
permitted by the terms of the related Mortgage Note, under any “due-on-sale” clause applicable thereto; provided,
however, that the Master Servicer shall not exercise any such right if the due-on-sale clause, in the reasonable belief of the
Master Servicer, is not enforceable under applicable law or if such exercise would result in non-coverage of any resulting loss
that would otherwise be covered under any insurance policy. In the event the Master Servicer is prohibited from exercising such
right, the Master Servicer is authorized to take or enter into an assumption and modification agreement from or with the Person to
whom a Mortgaged Property has been or is about to be conveyed, pursuant to which such Person becomes liable under the Mortgage Note
and, unless prohibited by applicable state law or unless the Mortgage Note contains a provision allowing a qualified borrower to
assume the Mortgage Note, the Mortgagor remains liable thereon; provided that the Mortgage Loan shall continue to be covered (if so
covered before the Master Servicer enters such agreement) by any related Primary Insurance Policy. The Master Servicer is also
authorized to enter into a substitution of liability agreement with such Person, pursuant to which the original Mortgagor is
released from liability and such Person is substituted as Mortgagor and becomes liable under the Mortgage Note.  The Master
Servicer shall not enter into any substitution or assumption with respect to a Mortgage Loan if such substitution or assumption
shall (i) both constitute a “significant modification” effecting an exchange or reissuance of such Mortgage Loan under
the Code (or Treasury regulations promulgated thereunder) and cause the REMICs to fail to qualify as a REMIC under the REMIC
Provisions or (ii) cause the imposition of any tax on “prohibited transactions” or “contributions” after
the startup day under the REMIC Provisions.  The Master Servicer shall notify the Trustee that any such substitution or
assumption agreement has been completed by forwarding to the Trustee the original copy of such substitution or assumption agreement
and other documents and instruments constituting a part thereof. In connection with any such assumption or substitution agreement,
the terms of the related Mortgage Note shall not be changed. Any fee collected by the applicable Servicer for entering into an
assumption or substitution of liability agreement shall be retained by such Servicer as additional servicing
compensation.


Notwithstanding the foregoing paragraph or any other provision of this
Agreement, the Master Servicer shall not be deemed to be in default, breach or otherwise in violation of any of its obligations
hereunder by reason of any assumption of a Mortgage Loan by operation of law or any assumption which the Master Servicer may be
restricted by law from preventing, for any reason whatsoever.


Section
3.09.        Realization Upon Defaulted Mortgage Loans.
The Master Servicer shall foreclose upon or otherwise comparably convert, or cause to be foreclosed upon or comparably converted,
the ownership of any Mortgaged Property securing a Mortgage Loan which comes into and continues in default and as to which no
satisfactory arrangements can be made for collection of delinquent payments pursuant to Section 3.01. In lieu of such foreclosure
or other conversion, and taking into consideration the desirability of maximizing net Liquidation Proceeds after taking into
account the effect of Insurance Proceeds upon Liquidation Proceeds, the Master Servicer may, to the extent consistent with prudent
mortgage loan servicing practices, accept a payment of less than the outstanding Principal Balance of a delinquent Mortgage Loan in
full satisfaction of the indebtedness evidenced by the related Mortgage Note and release the lien of the related Mortgage upon
receipt of such payment. The Master Servicer shall not foreclose upon or otherwise comparably convert a Mortgaged Property if the
Master Servicer is aware of evidence of toxic waste, other hazardous substances or other evidence of environmental contamination
thereon and the Master Servicer determines that it would be imprudent to do so. In connection with such foreclosure or other
conversion, the Master Servicer shall cause to be followed such practices and procedures as it shall deem necessary or advisable
and as shall be normal and usual in general mortgage servicing activities. The foregoing is subject to the provision that, in the
case of damage to a Mortgaged Property from an Uninsured Cause, the Master Servicer shall not be required to advance its own funds
towards the restoration of the property unless it shall be determined in the sole judgment of the Master Servicer, (i) that such
restoration will increase the proceeds of liquidation of the Mortgage Loan to Certificateholders after reimbursement to itself for
such expenses, and (ii) that such expenses will be recoverable to it through Liquidation Proceeds. The Master Servicer shall be
responsible for all other costs and expenses incurred by it in any such proceedings; provided, however, that it shall be
entitled to reimbursement thereof (as well as its normal servicing compensation) as an advance. The Master Servicer shall maintain
information required for tax reporting purposes regarding any Mortgaged Property which is abandoned or which has been foreclosed or
otherwise comparably converted. The Master Servicer shall report such information to the Internal Revenue Service and the Mortgagor
in the manner required by applicable law.


The Master Servicer may enter into one or more special servicing
agreements with a Lowest Class B Owner, subject to each Rating Agency's acknowledgment that the Ratings of the Certificates in
effect immediately prior to the entering into of such agreement would not be qualified, downgraded or withdrawn and the
Certificates would not be placed on credit review status (except for possible upgrading) as a result of such agreement.  Any
such agreement may contain provisions whereby such Lowest Class B Owner may (a) instruct the Master Servicer to instruct a Servicer
to the extent permitted under the applicable Selling and Servicing Contract to commence or delay foreclosure proceedings with
respect to related delinquent Mortgage Loans, provided that the Lowest Class B Owner deposits a specified amount of cash with the
Master Servicer that will be available for distribution to Certificateholders if Liquidation Proceeds are less than they otherwise
may have been had the Servicer acted pursuant to its normal servicing procedures, (b) purchase such delinquent Mortgage Loans from
the Trust immediately prior to the commencement of foreclosure proceedings at a price equal to the aggregate outstanding Principal
Balance of such Mortgage Loans plus accrued interest thereon at the applicable Mortgage Interest Rate through the last day of the
month in which such Mortgage Loans are purchased and/or (c) assume all of the servicing rights and obligations with respect to such
delinquent Mortgage Loans so long as (i) the Master Servicer has the right to transfer the servicing rights and obligations of such
Mortgage Loans to another servicer and (ii) such Lowest Class B Owner will service such Mortgage Loans in accordance with the
applicable Selling and Servicing Contract.


REMIC I shall not acquire any real property (or personal property
incident to such real property) except in connection with a default or imminent default of a Mortgage Loan. In the event that REMIC
I acquires any real property (or personal property incident to such real property) in connection with a default or imminent default
of a Mortgage Loan, such property shall be disposed of by the Master Servicer as soon as practicable in a manner that, consistent
with prudent mortgage loan servicing practices, maximizes the net present value of the recovery to the Trust, but in any event
within three years after its acquisition by the Master Servicer for REMIC I unless the Master Servicer provides to the Trustee an
Opinion of Counsel to the effect that the holding by REMIC I of such Mortgaged Property subsequent to three years after its
acquisition will not result in the imposition of taxes on “prohibited transactions” of REMIC I as defined in Section
860F of the Code or under the law of any state in which real property securing a Mortgage Loan owned by REMIC I is located or cause
REMIC I to fail to qualify as a REMIC for federal income tax purposes or for state tax purposes under the laws of any state in
which real property securing a Mortgage Loan owned by REMIC I is located at any time that any Certificates are outstanding. The
Master Servicer shall conserve, protect and operate each such property for the Certificateholders solely for the purpose of its
prompt disposition and sale in a manner which does not cause such property to fail to qualify as “foreclosure property”
within the meaning of Section 860G(a)(8) or result in the receipt by the REMIC of any “income from non-permitted
assets” within the meaning of Section 860F(a)(2)(B) of the Code or any “net income from foreclosure property”
which is subject to taxation under the REMIC Provisions. Pursuant to its efforts to sell such property, the Master Servicer shall
either itself or through an agent selected by the Master Servicer protect and conserve such property in the same manner and to such
extent as is customary in the locality where such property is located and may, incident to its conservation and protection of the
assets of the Trust, rent the same, or any part thereof, as the Master Servicer deems to be in the best interest of the Master
Servicer and the Trust for the period prior to the sale of such property. Additionally, the Master Servicer shall perform the tax
withholding and shall file information returns with respect to the receipt of mortgage interests received in a trade or business,
the reports of foreclosures and abandonments of any Mortgaged Property and the information returns relating to cancellation of
indebtedness income with respect to any Mortgaged Property required by Sections 6050H, 6050J and 6050P, respectively, of the Code,
and deliver to the Trustee an Officers’ Certificate on or before March 31 of each year stating that such reports have been
filed.  Such reports shall be in form and substance sufficient to meet the reporting requirements imposed by Sections 6050H,
6050J and 6050P of the Code.


Notwithstanding any other provision of this Agreement, the Master
Servicer and the Trustee, as applicable, shall comply with all federal withholding requirements with respect to payments to
Certificateholders of interest or original issue discount that the Master Servicer or the Trustee reasonably believes are
applicable under the Code.  The consent of Certificateholders shall not be required for any such withholding.  Without
limiting the foregoing, the Master Servicer agrees that it will not withhold with respect to payments of interest or original issue
discount in the case of a Certificateholder that has furnished or caused to be furnished an effective Form W-8 or an acceptable
substitute form or a successor form and who is not a “10 percent shareholder” within the meaning of Code Section
871(h)(3)(B) or a “controlled foreign corporation” described in Code Section 881(c)(3)(C) with respect to REMIC I,
REMIC II or the  depositor.  In the event the Trustee withholds any amount from interest or original issue discount
payments or advances thereof to any Certificateholder pursuant to federal withholding requirements, the Trustee shall indicate the
amount withheld to such Certificateholder.


Section
3.10.        Trustee to Cooperate; Release of Mortgage Files. Upon the Payoff or scheduled maturity of any Mortgage Loan, the Master Servicer shall cause such final payment to be
immediately deposited in the related Custodial Account for P&I or the Investment Account.  The Master Servicer shall
promptly notify the Trustee thereof by a certification (which certification shall include a statement to the effect that all
amounts received in connection with such payment which are required to be deposited in either such account have been so deposited)
of a Servicing Officer and shall request delivery to it of the Mortgage File; provided, however, that such certification
shall not be required if the Mortgage File is held by a Custodian which is also the Servicer of the Mortgage Loan. Upon receipt of
such certification and request, the Trustee shall, not later than the fifth succeeding Business Day, release, or cause to be
released, the related Mortgage File to the Master Servicer or the applicable Servicer indicated in such request. With any such
Payoff or other final payment, the Master Servicer is authorized (i) to prepare for and procure from the trustee or mortgagee under
the Mortgage which secured the Mortgage Note a deed of full reconveyance or other form of satisfaction or assignment of Mortgage
and endorsement of Mortgage Note in connection with a refinancing covering the Mortgaged Property, which satisfaction, endorsed
Mortgage Note or assigning document shall be delivered by the Master Servicer to the person or persons entitled thereto, and (ii)
with respect to any MERS Loan, to cause the removal of such Mortgage Loan from registration on the MERS® System. No expenses
incurred in connection with such satisfaction or assignment shall be payable to the Master Servicer by the Trustee or from the
Certificate Account, the related Investment Account or the related Custodial Account for P&I. From time to time as appropriate
for the servicing or foreclosure of any Mortgage Loan, including, for this purpose, collection under any Primary Insurance Policy,
the Trustee shall, upon request of the Master Servicer and delivery to it of a trust receipt signed by a Servicing Officer, release
not later than the fifth Business Day following the date of receipt of such request and trust receipt the related Mortgage File to
the Master Servicer or the related Servicer as indicated by the Master Servicer and shall execute such documents as shall be
necessary to the prosecution of any such proceedings. Such trust receipt shall obligate the Master Servicer to return the Mortgage
File to the Trustee when the need therefor by the Master Servicer no longer exists, unless the Mortgage Loan shall be liquidated,
in which case, upon receipt of a certificate of a Servicing Officer similar to that herein above specified, the trust receipt shall
be released by the Trustee to the Master Servicer.


Section
3.11.        Compensation to the Master Servicer and the Servicers. As compensation for its activities hereunder, the Master Servicer shall be entitled to receive from the Investment
Account and the Certificate Account the amounts provided for by Section 3.05(a)(iii). The Master Servicer shall be required to pay
all expenses incurred by it in connection with its activities hereunder and shall not be entitled to reimbursement therefor, except
as specifically provided herein.


As compensation for its activities under the applicable Selling and
Servicing Contract, the applicable Servicer shall be entitled to withhold or withdraw from the related Custodial Account for
P&I the amounts provided for in such Selling and Servicing Contract to the extent not inconsistent with this Agreement
(including Section 3.05(d)). Each Servicer is required to pay all expenses incurred by it in connection with its servicing
activities under its Selling and Servicing Contract (including payment of premiums for Primary Insurance Policies, other than
Special Primary Insurance Policies, if required) and shall not be entitled to reimbursement therefor except as specifically
provided in such Selling and Servicing Contract and not inconsistent with this Agreement.


Section
3.12.        Reports to the Trustee; Certificate Account Statement. Not later than 15 days after each Distribution Date, the Master Servicer shall forward a statement, certified by a
Servicing Officer, to the Trustee setting forth the status of the Certificate Account as of the close of business on such
Distribution Date and showing, for the period covered by such statement, the aggregate of deposits into and withdrawals from the
Certificate Account for each category of deposit specified in Section 3.04 and each category of withdrawal specified in Section
3.05, and stating that all distributions required by this Agreement have been made (or if any required distribution has not been
made, specifying the nature and amount thereof).  The Trustee shall make available such statements to any Certificateholder
upon request at the expense of the Master Servicer.  Such statement shall also, to the extent available, include information
regarding delinquencies on the Mortgage Loans, indicating the number and aggregate Principal Balance of Mortgage Loans which are
one, two, three or more months delinquent, the number and aggregate Principal Balance of Mortgage Loans with respect to which
foreclosure proceedings have been initiated and the book value of any Mortgaged Property acquired by the Trust through foreclosure,
deed in lieu of foreclosure or other exercise of the Trust’s security interest in the Mortgaged Property.


Section
3.13.        Annual Statement as to Compliance. The
Master Servicer shall deliver to the Trustee, on or before April 30 of each year, beginning with the first April 30 succeeding the
Cut-Off Date by at least six months, an Officer’s Certificate stating as to the signer thereof, that (i) a review of the
activities of the Master Servicer during the preceding calendar year and performance under this Agreement has been made under such
officer’s supervision, and (ii) to the best of such officer’s knowledge, based on such review, the Master Servicer has
fulfilled all its obligations under this Agreement throughout such year, or, if there has been a default in the fulfillment of any
such obligation, specifying each such default known to such officer and the nature and status thereof. Copies of such statement
shall be provided by the Master Servicer to Certificateholders upon request or by the Trustee (solely to the extent that such
copies are available to the Trustee) at the expense of the Master Servicer, should the Master Servicer fail to so provide such
copies.


Section
3.14.        Access to Certain Documentation and Information Regarding the Mortgage
Loans. In the event that the Certificates are legal for investment by
federally-insured savings associations, the Master Servicer shall provide to the OTS, the FDIC and the supervisory agents and
examiners of the OTS and the FDIC access to the documentation regarding the related Mortgage Loans required by applicable
regulations of the OTS or the FDIC, as applicable, and shall in any event provide such access to the documentation regarding such
Mortgage Loans to the Trustee and its representatives, such access being afforded without charge, but only upon reasonable request
and during normal business hours at the offices of the Master Servicer designated by it.


Section
3.15.        Annual Independent Public Accountants’ Servicing Report. On or before April 30 of each year, beginning with the first April 30 succeeding the Cut-Off Date by at
least six months, the Master Servicer, at its expense, shall furnish to the Trustee a copy of a report delivered to the Master
Servicer by a firm of independent public accountants (who may also render other services to the Master Servicer or any affiliate
thereof) to the effect that, on the basis of an examination conducted by such firm in accordance with standards established by the
American Institute of Certified Public Accountants, the Master Servicer has complied with certain minimum residential mortgage loan
servicing standards in its role as Master Servicer with respect to the servicing of residential mortgage loans (including the
Mortgage Loans) during the most recently completed fiscal year.  In rendering its report such firm may rely, (a) as to matters
relating to the Certificates, upon a statistical sampling of series of mortgage-backed certificates which may include the
Certificates and (b) as to matters relating to the direct servicing of residential mortgage loans by subservicers, upon comparable
reports of firms of independent certified public accountants rendered on the basis of examinations conducted in accordance with the
same standards (rendered within one year of such report) with respect to those subservicers.


Section
3.16.        Yield Maintenance Account. On or prior to
the Closing Date, the Trustee shall cause to be established and maintained the Yield Maintenance Account, into which amounts
distributed pursuant to the Yield Maintenance Agreement shall be deposited for the benefit of the Class A (other than the
Class A-3 Certificates) and Class Y Certificates.  On each Distribution Date, the Trustee shall withdraw from the Yield
Maintenance Account the amounts on deposit therein, and deposit such amounts in the Certificate Account for payment to the
Class A (other than the Class A-3 Certificates) and Class Y Certificates pursuant to Section 4.04(a).


            Amounts on deposit in the Yield Maintenance Account shall
not be invested and shall not be held in an interest-bearing account.


To the extent that it
constitutes a “reserve fund” for purposes of the REMIC Provisions, the Yield Maintenance Account established hereunder
shall be an “outside reserve fund” as defined in Treasury Regulation 1.860G-2(h), and in that regard (i) such fund
shall be an outside reserve fund and not an asset of any REMIC, (ii) such fund shall be owned for federal tax purposes by the
Holder of the Class Y Certificates, and the Holder of the Class Y Certificates shall report all amounts of income, deduction, gain
or loss accruing therefrom, and (iii) amounts transferred by the REMIC to the fund shall be treated as distributed by the REMIC to
the Holder of the Class Y Certificates.


Section
3.17.        [Reserved.]


Section 3.18.        [Reserved.]


Section 3.19.        Determination of LIBOR by Master Servicer.  


(a)        With respect to each Distribution Date, the Master Servicer will determine
LIBOR on the related LIBOR Determination Date on the basis of the “Interest
Settlement Rate” for United States dollar deposits of one-month maturity set by the British Bankers’ Association (the
“BBA”) as of 11:00 a.m. (London time) on such LIBOR Determination Date as found on any of the Moneyline Telerate
Service (formerly the Dow Jones Markets) page 3750, the Reuters Monitor Money Rates Service page “LIBOR01” or the
Bloomberg L.P. page “BBAM” (each such page, or such other page as may replace any of the foregoing on such service or
such other service as may be nominated by the BBA as the information vendor for the purpose of displaying the BBA’s Interest
Settlement Rates for deposits in United States dollars, each, a “Designated Telerate Page”).


(b)        If on any LIBOR Determination Date, such Interest Settlement Rates are not
available from any Designated Telerate Page, LIBOR for the related accrual period will be the most recently published Interest
Settlement Rate.  In the event that the BBA no longer sets an Interest Settlement Rate, the Master Servicer shall calculate
LIBOR for the immediately following accrual period as follows:  the Master Servicer will determine LIBOR by reference to the
quotations offered by the principal London office of each of the designated Reference Banks meeting the criteria set forth below
for making one-month United States dollar deposits in leading banks in the London Interbank market, as of 11:00 a.m. (London time)
on the LIBOR Determination Date.  Under this method LIBOR will be established by the Master Servicer on each LIBOR
Determination Date as follows:


(i)         If on any LIBOR
Determination Date two or more Reference Banks provide offered quotations, LIBOR for the next interest accrual period shall be the
arithmetic mean of the offered quotations, carrying the result (expressed as a percentage) out to six decimal places, and rounding
to five decimal places.


(ii)        If on any LIBOR
Determination Date only one or none of the Reference Banks provides offered quotations, LIBOR for the next interest accrual period
shall be the greater of:


·        LIBOR as determined on the previous LIBOR Determination Date
or


·        the Reserve Interest Rate.


The “Reserve Interest Rate” shall be the rate per annum
that the Master Servicer determines to be either:


·        the arithmetic mean, (expressed as a percentage) carried out
to six decimal places, and rounded to five decimal places, of the one-month United States dollar lending rates that New York City
banks selected by the Master Servicer are quoting, on the relevant LIBOR Determination Date, to the principal London offices of at
least two of the Reference Banks to which the quotations are, in the opinion of the Master Servicer, being so made, or


·        if the Master Servicer cannot determine the arithmetic mean,
the lowest one-month United States dollar lending rate which New York City banks selected by the Master Servicer are quoting on the
LIBOR Determination Date to leading European banks.


(iii)       If on any LIBOR
Determination Date the Master Servicer is required but is unable to determine the Reserve Interest Rate in the manner provided in
paragraph (ii) above, LIBOR for the next interest accrual period shall be LIBOR as determined on the preceding LIBOR Determination
Date, or, in the case of the first LIBOR Determination Date, LIBOR shall be considered to be the per annum rate specified in the
Prospectus Supplement, if so specified.


Each Reference Bank (i) will be a leading
bank engaged in transactions in Eurodollar deposits in the international Eurocurrency market, (ii) will not control, be controlled
by, or be under common control with, the Master Servicer and (iii) will have an established place of business in London.  If
any Reference Bank should be unwilling or unable to act as such or if the Master Servicer should terminate the designation of any
such reference bank, the Master Servicer will promptly designate another leading bank meeting the criteria specified above. 
If on any such LIBOR Determination Date, the Master Servicer calculates LIBOR on the basis of the provisions of this
Section 3.19(b), the Master Servicer shall designate the Reference Banks. 


(c)        The establishment of
LIBOR on each LIBOR Determination Date by the Master Servicer for the related accrual period will, in the absence of manifest
error, be final and binding.


Section
3.20.        Assumption or Termination of Selling and Servicing Contracts by Trustee. In the event the Master Servicer, or any successor Master Servicer, shall for any reason no
longer be the Master Servicer (including by reason of an Event of Default), the Trustee as trustee hereunder or its designee shall
thereupon assume all of the rights and obligations of the Master Servicer under the Selling and Servicing Contracts with respect to
the related Mortgage Loans unless the Trustee elects to terminate the Selling and Servicing Contracts with respect to such Mortgage
Loans in accordance with the terms thereof. The Trustee, its designee or the successor servicer for the Trustee shall be deemed to
have assumed all of the Master Servicer’s interest therein with respect to the related Mortgage Loans and to have replaced
the Master Servicer as a party to the Selling and Servicing Contracts to the same extent as if the rights and duties under the
Selling and Servicing Contracts relating to such Mortgage Loans had been assigned to the assuming party, except that the Master
Servicer shall not thereby be relieved of any liability or obligations under the Selling and Servicing Contracts with respect to
the Master Servicer’s duties to be performed prior to its termination hereunder.


The Master Servicer at its expense shall, upon request of the Trustee,
deliver to the assuming party all documents and records relating to the Selling and Servicing Contracts and the Mortgage Loans then
being master serviced by the Master Servicer and an accounting of amounts collected and held by the Master Servicer and otherwise
use its best efforts to effect the orderly and efficient transfer of the rights and duties under the related Selling and Servicing
Contracts relating to such Mortgage Loans to the assuming party.


ARTICLE IV



Payments to Certificateholders; Payment of Expenses


Section
4.01.        Distributions to Holders of REMIC I Regular Interests and Class R-1 Residual
Interest.  On each Distribution Date, the Trustee (or any duly
appointed paying agent) (i) shall be deemed to have distributed from the Certificate Account the REMIC I Distribution Amount to the
Holders of the REMIC I Regular Interests, and to have deposited such amount for their benefit into the Certificate Account and (ii)
from the Certificate Account shall distribute to the Class R Certificateholders, in accordance with the written statement received
from the Master Servicer pursuant to Section 4.02(b), the sum of (a) the Excess Liquidation Proceeds and (b) the amounts to be
distributed to the Holders of the Class R-1 Residual Interest pursuant to the definition of “REMIC I Distribution
Amount” for such Distribution Date.  Amounts distributed pursuant to clause (ii) above shall be distributed by wire
transfer in immediately available funds for the account of each Class R Certificateholder, or by any other means of payment
acceptable to each Class R Certificateholder of record on the immediately preceding Record Date (other than as provided in Section
9.01 respecting the final distribution), as specified by each such Certificateholder and at the address of such Holder appearing in
the Certificate Register.  Notwithstanding any other provision of this Agreement, no actual distributions pursuant to clause
(i) of this Section 4.01 shall be made on account of the deemed distributions described in this paragraph except in the event of a
liquidation of REMIC II and not REMIC I.


Section 4.02.        Advances by the Master Servicer; Distribution Reports to the Trustee.


(a)        To the extent described
below, the Master Servicer is obligated to advance its own funds to the Certificate Account to cover any shortfall between (i)
Minimum Monthly Payments scheduled to be received in respect of Mortgage Loans and (ii) the amounts actually deposited in the
Certificate Account on account of such payments (including amounts advanced by a Servicer pursuant to a Selling and Servicing
Contract).  The Master Servicer’s obligation to make any advance or advances described in this Section 4.02 is effective
only to the extent that such advance is, in the good faith judgment of the Master Servicer made on or before the second Business
Day prior to each Distribution Date, reimbursable from Insurance Proceeds or Liquidation Proceeds of the related Mortgage Loans or
recoverable as late Monthly Payments with respect to the related Mortgage Loans or otherwise.


Prior to the close of business on the second Business Day prior to
each Distribution Date, the Master Servicer shall determine whether or not it will make a Monthly P&I Advance on the Business
Day prior to such Distribution Date (in the event that the applicable Servicer fails to make such advances) and shall furnish a
written statement to the Trustee, the Paying Agent, if any, and to any Certificateholder requesting the same, setting forth the
aggregate amount to be advanced on account of principal and interest in respect of the Mortgage Loans, stated
separately.


In the event that the Master Servicer shall be required to make a
Monthly P&I Advance, it shall on the Business Day prior to the related Distribution Date either (i) deposit in the Certificate
Account an amount equal to such Monthly P&I Advance, (ii) make an appropriate entry in the records of the Certificate Account
that funds in such account being held for future distribution or withdrawal have been, as permitted by this Section 4.02, used by
the Master Servicer to make such Monthly P&I Advance or (iii) make advances in the form of any combination of (i) and (ii)
aggregating the amount of such Monthly P&I Advance.  Any funds being held for future distribution to Certificateholders
and so used shall be replaced by the Master Servicer by deposit in the Certificate Account on the Business Day immediately
preceding any future Distribution Date to the extent that funds in the Certificate Account on such Distribution Date with respect
to the Mortgage Loans shall be less than payments to Certificateholders required to be made on such date with respect to the
Mortgage Loans.  Under each Selling and Servicing Contract, the Master Servicer is entitled to receive from the Custodial
Accounts for P&I established by the Servicers amounts received by the applicable Servicers on particular Mortgage Loans as late
payments of principal and interest or as Liquidation or Insurance Proceeds and respecting which the Master Servicer has made an
unreimbursed advance of principal and interest.  The Master Servicer is also entitled to receive other amounts from the
related Custodial Accounts for P&I established by the Servicers to reimburse itself for prior Nonrecoverable Advances
respecting Mortgage Loans serviced by such Servicers.  The Master Servicer shall deposit these amounts in the Investment
Account prior to withdrawal pursuant to Section 3.05.


In accordance with Section 3.05, Monthly P&I Advances are
reimbursable to the Master Servicer from cash in the Investment Account or the Certificate Account to the extent that the Master
Servicer shall determine that any such advances previously made are Nonrecoverable Advances pursuant to Section 4.03.


(b)        Prior to noon New York
City time two Business Days prior to each Distribution Date, the Master Servicer shall provide (x) the Trustee and (y) the Company
(if the Company is no longer acting as Master Servicer) with a statement in writing of (1) the amount, as applicable, of (i)
interest, (ii) the interest portion, if any, of Realized Losses, (iii) Uncompensated Interest Shortfall, (iv) scheduled principal,
(v) Net Negative Amortization Amounts, (vi) Principal Prepayments, (vii) Liquidation Principal, (viii) Subsequent Recoveries, (ix)
the principal portion of Realized Losses (after giving effect to any reduction thereof by application of any Cumulative
Carry-Forward Subsequent Recoveries Amount), (x) the Residual Distribution Amount and (xi) the Excess Liquidation Proceeds to
be distributed or allocated, as applicable, to each Class of Certificates on such Distribution Date (such amounts to be determined
in accordance with the definitions of “REMIC I Distribution Amount” and “REMIC II Distribution Amount,”
Section 4.01 and Section 4.04 hereof and other related definitions set forth in Article I hereof); (2) the applicable Class
Principal Balance after giving effect to such distributions and allocations; (3) the Cumulative Carry-Forward Subsequent Recoveries
Amount for such Distribution Date; (4) the amount of any Special Primary Insurance Premium payable on such Distribution Date; (5)
for each Class of the Class A Certificates (other than the Class A-3 Certificates), any portion of the Carryover Shortfall
Amount for such Class remaining after distributions on such Distribution Date; and (6) the Yield Maintenance Payments for the Class
A (other than the Class A-3 Certificates) and Class Y Certificates for such Distribution Date.


Section
4.03.        Nonrecoverable Advances. Any advance
previously made by a Servicer pursuant to its Selling and Servicing Contract with respect to a Mortgage Loan or by the Master
Servicer that the Master Servicer shall determine in its good faith judgment not to be ultimately recoverable from Insurance
Proceeds or Liquidation Proceeds or otherwise with respect to such Mortgage Loan or recoverable as late Monthly Payments with
respect to such Mortgage Loan shall be a Nonrecoverable Advance.  The determination by the Master Servicer that it or the
applicable Servicer has made a Nonrecoverable Advance or that any advance would constitute a Nonrecoverable Advance, shall be
evidenced by an Officer’s Certificate of the Master Servicer delivered to the Trustee on the Determination Date and detailing
the reasons for such determination.  Notwithstanding any other provision of this Agreement, any insurance policy relating to
the Mortgage Loans, or any other agreement relating to the Mortgage Loans to which the Company or the Master Servicer is a party,
(a) the Master Servicer and each Servicer shall not be obligated to, and shall not, make any advance that, after reasonable inquiry
and in its sole discretion, the Master Servicer or such Servicer shall determine would be a Nonrecoverable Advance and (b) the
Master Servicer and each Servicer shall be entitled to reimbursement for any advance as provided in Section 3.05(a)(i), (ii) and
(iv) and Section 3.05(d) of this Agreement.


Section 4.04.        Distributions to Certificateholders; Payment of Special Primary Insurance Premiums. 


(a)        On each Distribution Date, the Trustee (or any duly appointed paying
agent) shall (i) subject to Section 3.05(a)(viii), withdraw from the Certificate Account any Special Primary Insurance
Premium payable on such Distribution Date and pay such amount to the insurer under the applicable Special Primary Insurance Policy
and (ii) withdraw from the Certificate Account the REMIC II Available Distribution Amount for such Distribution Date and
distribute, from the amount so withdrawn, to the extent of the REMIC II Available Distribution Amount, the REMIC II Distribution
Amount to the Holders of the REMIC II Regular Interests and the Class R-2 Residual Interest. 


Notwithstanding the immediately
preceding sentence, on each Distribution Date, the Trustee (or any duly appointed paying agent) shall, from the amount otherwise
distributable to the Class X-L Regular Interest on such Distribution Date pursuant to the immediately preceding sentence,
distribute, to the extent thereof, to the Holders of each Class of Class A Certificates (other than the Class A-3
Certificates), the Carryover Shortfall Payment, if any, for each such Class.  Each Holder of a Class X Certificate is deemed
to have accepted the terms for payment of the Carryover Shortfall Payments to the Holders of the Class A Certificates (other than
the Class A-3 Certificates) pursuant to the immediately preceding sentence and the provisions of Section 2.16.  Each
Holder of a Class A (other than a Class A-3 Certificate) or Class X Certificate is deemed, by acceptance of such Certificate,
to have accepted the provisions of Section 2.16.


Furthermore, on each Distribution Date
from and including March 2005 to and including August 2013, the Trustee shall withdraw from the Certificate Account and distribute
to the Holders of the Class A (other than the Class A-3 Certificates) and Class Y Certificates, the applicable Yield
Maintenance Payment.


The net distributions to the
Certificates pursuant to this Section 4.04(a) shall be made in accordance with the written statement received from the Master
Servicer pursuant to Section 4.02(b).  Any Special Primary Insurance Premiums distributed pursuant to clause (i) above shall
be distributed by any method specified in the respective Special Primary Insurance Policy as directed by the related insurer to the
Master Servicer.  Amounts distributed to the Certificateholders pursuant to clause (ii) above shall be distributed by wire
transfer in immediately available funds for the account of, or by check mailed to, each such Certificateholder of record on the
immediately preceding Record Date (other than as provided in Section 9.01 respecting the final distribution), as specified by each
such Certificateholder and at the address of such Holder appearing in the Certificate Register. 


(b)        All reductions in the
Certificate Principal Balance of a Certificate effected by distributions of principal and all allocations of Realized Losses made
on any Distribution Date shall be binding upon all Holders of such Certificate and of any Certificate issued upon the registration
of transfer or exchange therefor or in lieu thereof, whether or not such distribution is noted on such Certificate.  The final
distribution of principal of each Certificate (and the final distribution upon the Class R Certificates upon (i) the termination of
REMIC I and REMIC II and (ii) the payment, or making provision for payment, of all liabilities of the Trust) shall be payable in
the manner provided above only upon presentation and surrender thereof on or after the Distribution Date therefor at the office or
agency of the Certificate Registrar specified in the notice delivered pursuant to Section 4.04(c)(ii) and Section
9.01(b).


(c)        Whenever, on the basis
of Curtailments, Payoffs and Monthly Payments on the Mortgage Loans and Insurance Proceeds and Liquidation Proceeds received and
expected to be received during the Payoff Period, the Master Servicer has notified the Trustee in writing by the 15th day of the
month that it believes that the entire remaining unpaid Class Principal Balance of any Class of Certificates will become
distributable on the next Distribution Date, the Trustee shall, no later than the 18th day of the month of such Distribution Date,
mail or cause to be mailed to each Person in whose name a Certificate to be so retired is registered at the close of business on
the Record Date and to the Rating Agencies a notice to the effect that:


(i)                  it is
expected that funds sufficient to make such final distribution will be available in the Certificate Account on such Distribution
Date, and


(ii)                if such funds are
available, (A) such final distribution will be payable on such Distribution Date, but only upon presentation and surrender of such
Certificate at the office or agency of the Certificate Registrar maintained for such purpose (the address of which shall be set
forth in such notice), and (B) no interest shall accrue on such Certificate after such Distribution Date.


Section
4.05.        Statements to Certificateholders. With
each distribution from the Certificate Account on a Distribution Date, the Trustee shall send to each Rating Agency and shall make
available to each Certificateholder the statement required by Section 4.02(b).  The Trustee may make available such statement
and certain other information, including, without limitation, information required to be provided by the Trustee pursuant to
Sections 3.12 and 3.13, to Certificateholders through the Trustee’s web site. Such web site is currently located at
“https://www.tss.db.com/invr”.  Assistance in using the web site can currently be obtained by calling the
Trustee’s investor relations desk at 800-735-7777. Parties unable to use this distribution method may request that a paper
copy be mailed to them via first class mail by calling the investor relations desk. The location of such web page and the
procedures used therein are subject to change from time to time at the Trustee’s discretion.


Upon request by any Certificateholder or Rating Agency or the Trustee,
the Master Servicer shall forward to such Certificateholder or Rating Agency and the Trustee and the Company (if the Company is no
longer acting as Master Servicer) an additional report which sets forth with respect to the Mortgage Loans:


(a)       
The number and aggregate Principal Balance of the Mortgage Loans delinquent one, two and three months or more;


(b)       
The (i) number and aggregate Principal Balance of Mortgage Loans with respect to which foreclosure proceedings have been initiated
and (ii) the number and aggregate book value of Mortgaged Properties acquired through foreclosure, deed in lieu of foreclosure or
other exercise of rights respecting the Trust’s security interest in the Mortgage Loans; and


(c)       
The cumulative amount of Realized Losses allocated to the related Certificates since the Cut-Off Date.


Upon request by any Certificateholder, the Master Servicer, as soon as
reasonably practicable, shall provide the requesting Certificateholder with such information as is necessary and appropriate, in
the Master Servicer’s sole discretion, for purposes of satisfying applicable reporting requirements under Rule 144A of the
Securities Act.


The Company may make available any reports, statements or other
information to Certificateholders through the Company’s home page on the world wide web.  As of the Closing Date, such
web page is located at “www.wamumsc.com” and information is available by clicking on “Investor
Information.”


ARTICLE V



The Certificates


Section 5.01.        The Certificates.


(a)        The Certificates shall
be substantially in the forms set forth in Exhibit A and B with the additional insertion from Exhibit H attached hereto, and shall
be executed by the Trustee on behalf of the Trust, authenticated by the Trustee (or any duly appointed Authenticating Agent) and
delivered (i) upon and pursuant to the order of the Company and (ii) upon receipt by the Trustee of the documents specified in
Section 2.01. The Certificates shall be issuable in Authorized Denominations. Certificates shall be executed by manual or facsimile
signature on behalf of the Trust by authorized officers of the Trustee. Certificates bearing the manual or facsimile signatures of
individuals who were at the time of execution the proper officers of the Trustee shall bind the Trust, notwithstanding that such
individuals or any of them have ceased to hold such offices prior to the authentication and delivery of such Certificates or did
not hold such offices at the date of such Certificates. No Certificate shall be entitled to any benefit under this Agreement, or be
valid for any purpose, unless there appears on such Certificate a certificate of authentication substantially in the form provided
for herein executed by the Trustee or any Authenticating Agent by manual signature, and such certificate upon any Certificate shall
be conclusive evidence, and the only evidence, that such Certificate has been duly authenticated and delivered hereunder. All
Certificates shall be dated the date of their authentication.


(b)        The following
definitions apply for purposes of this Section 5.01: “Disqualified Organization” means any Person which is not a
Permitted Transferee, but does not include any “Pass-Through Entity” which owns or holds a Residual Certificate and of
which a Disqualified Organization, directly or indirectly, may be a stockholder, partner or beneficiary; “Pass-Through
Entity” means any regulated investment company, real estate investment trust, common trust fund, partnership, trust or
estate and any organization to which Section 1381 of the Code applies; “Ownership Interest” means, with respect
to any Residual Certificate, any ownership or security interest in such Residual Certificate, including any interest in a Residual
Certificate as the Holder thereof and any other interest therein whether direct or indirect, legal or beneficial, as owner or as
pledgee; “Transfer” means any direct or indirect transfer or sale of, or directly or indirectly transferring or
selling any Ownership Interest in a Residual Certificate; and “Transferee” means any Person who is acquiring by
Transfer any Ownership Interest in a Residual Certificate.


(c)        Restrictions on
Transfers of the Residual Certificates to Disqualified Organizations are set forth in this Section 5.01(c).


(i)                  Each
Person who has or who acquires any Ownership Interest in a Residual Certificate shall be deemed by the acceptance or acquisition of
such Ownership Interest to have agreed to be bound by the following provisions and to have irrevocably authorized the Trustee or
its designee under clause (iii)(A) below to deliver payments to a Person other than such Person and to negotiate the terms of any
mandatory sale under clause (iii)(B) below and to execute all instruments of transfer and to do all other things necessary in
connection with any such sale. The rights of each Person acquiring any Ownership Interest in a Residual Certificate are expressly
subject to the following provisions:


(A)       Each
Person holding or acquiring any Ownership Interest in a Residual Certificate shall be a Permitted Transferee and shall promptly
notify the Trustee of any change or impending change in its status as a Permitted Transferee.


(B)       In
connection with any proposed Transfer of any Ownership Interest in a Residual Certificate to a U.S. Person, the Trustee shall
require delivery to it, and shall not register the Transfer of any Residual Certificate until its receipt of (1) an affidavit and
agreement (a “Transferee Affidavit and Agreement”) attached hereto as Exhibit J from the proposed Transferee, in
form and substance satisfactory to the Company, representing and warranting, among other things, that it is not a Non-U.S. Person,
that such transferee is a Permitted Transferee, that it is not acquiring its Ownership Interest in the Residual Certificate that is
the subject of the proposed Transfer as a nominee, trustee or agent for any Person who is not a Permitted Transferee, that for so
long as it retains its Ownership Interest in a Residual Certificate, it will endeavor to remain a Permitted Transferee, and that it
has reviewed the provisions of this Section 5.01(c) and agrees to be bound by them, and (2) a certificate, attached hereto as
Exhibit I, from the Holder wishing to transfer the Residual Certificate, in form and substance satisfactory to the Company,
representing and warranting, among other things, that no purpose of the proposed Transfer is to allow such Holder to impede the
assessment or collection of tax.


(C)      
Notwithstanding the delivery of a Transferee Affidavit and Agreement by a proposed Transferee under clause (B) above, if the
Trustee has actual knowledge that the proposed Transferee is not a Permitted Transferee, no Transfer of an Ownership Interest in a
Residual Certificate to such proposed Transferee shall be effected.


(D)       Each
Person holding or acquiring any Ownership Interest in a Residual Certificate agrees by holding or acquiring such Ownership Interest
(i) to require a Transferee Affidavit and Agreement from any other Person to whom such Person attempts to transfer its Ownership
Interest and to provide a certificate to the Trustee in the form attached hereto as Exhibit J; (ii) to obtain the express written
consent of the Company prior to any transfer of such Ownership Interest, which consent may be withheld in the Company’s sole
discretion; and (iii) to provide a certificate to the Trustee in the form attached hereto as Exhibit I.


(ii)                The Trustee shall
register the Transfer of any Residual Certificate only if it shall have received the Transferee Affidavit and Agreement, a
certificate of the Holder requesting such transfer in the form attached hereto as Exhibit J and all of such other documents as
shall have been reasonably required by the Trustee as a condition to such registration.


(iii)       (A)       If any “disqualified
organization” (as defined in Section 860E(e)(5) of the Code) shall become a holder of a Residual Certificate, then the last
preceding Permitted Transferee shall be restored, to the extent permitted by law, to all rights and obligations as Holder thereof
retroactive to the date of registration of such Transfer of such Residual Certificate. If any Non-U.S. Person shall become a holder
of a Residual Certificate, then the last preceding holder which is a U.S. Person shall be restored, to the extent permitted by law,
to all rights and obligations as Holder thereof retroactive to the date of registration of the Transfer to such Non-U.S. Person of
such Residual Certificate. If a transfer of a Residual Certificate is disregarded pursuant to the provisions of Treasury
Regulations Section 1.860E-1 or Section 1.860G-3, then the last preceding Permitted Transferee shall be restored, to the extent
permitted by law, to all rights and obligations as Holder thereof retroactive to the date of registration of such Transfer of such
Residual Certificate. Neither the Trust nor the Trustee shall be under any liability to any Person for any registration of Transfer
of a Residual Certificate that is in fact not permitted by this Section 5.01(c) or for making any payments due on such Certificate
to the holder thereof or for taking any other action with respect to such holder under the provisions of this
Agreement.


(B)       If any purported Transferee shall become a Holder of a Residual Certificate in
violation of the restrictions in this Section 5.01(c) and to the extent that the retroactive restoration of the rights of the
Holder of such Residual Certificate as described in clause (iii)(A) above shall be invalid, illegal or unenforceable, then the
Company shall have the right, without notice to the Holder or any prior Holder of such Residual Certificate, to sell such Residual
Certificate to a purchaser selected by the Company on such terms as the Company may choose. Such purported Transferee shall
promptly endorse and deliver each Residual Certificate in accordance with the instructions of the Company. Such purchaser may be
the Company itself or any affiliate of the Company. The proceeds of such sale, net of the commissions (which may include
commissions payable to the Company or its affiliates), expenses and taxes due, if any, shall be remitted by the Company to such
purported Transferee. The terms and conditions of any sale under this clause (iii)(B) shall be determined in the sole discretion of
the Company, and the Company shall not be liable to any Person having an Ownership Interest in a Residual Certificate as a result
of its exercise of such discretion.


(iv)       The Company, on behalf of the Trustee, shall make available, upon written request
from the Trustee, all information necessary to compute any tax imposed (A) as a result of the Transfer of an Ownership Interest in
a Residual Certificate to any Person who is not a Permitted Transferee, including the information regarding “excess
inclusions” of such Residual Certificates required to be provided to the Internal Revenue Service and certain Persons as
described in Treasury Regulation Section 1.860D-1(b)(5), and (B) as a result of any regulated investment company, real estate
investment trust, common trust fund, partnership, trust, estate or organizations described in Section 1381 of the Code having as
among its record holders at any time any Person who is not a Permitted Transferee. Reasonable compensation for providing such
information may be required by the Company from such Person.


(v)        The provisions of this Section 5.01 set forth prior to this Section (v) may be
modified, added to or eliminated by the Company and the Trustee, provided that there shall have been delivered to the Trustee the
following:


(A)       written notification from each of the Rating Agencies to the effect that the
modification, addition to or elimination of such provisions will not cause such Rating Agency to downgrade its then-current Ratings
of the Certificates; and


(B)       an Opinion of Counsel, in form and substance satisfactory to the Company (as
evidenced by a certificate of the Company), to the effect that such modification, addition to or absence of such provisions will
not cause REMIC I and REMIC II to cease to qualify as a REMIC and will not create a risk that (1) REMIC I and REMIC II may be
subject to an entity-level tax caused by the Transfer of any Residual Certificate to a Person which is not a Permitted Transferee
or (2) a Certificateholder or another Person will be subject to a REMIC-related tax caused by the Transfer of a Residual
Certificate to a Person which is not a Permitted Transferee.


(vi)       The
following legend shall appear on all Residual Certificates:


ANY RESALE, TRANSFER OR OTHER
DISPOSITION OF THIS CERTIFICATE MAY BE MADE ONLY IF THE PROPOSED TRANSFEREE PROVIDES A TRANSFER AFFIDAVIT TO THE COMPANY AND THE
TRUSTEE THAT (1) SUCH TRANSFEREE IS NOT EITHER (A) THE UNITED STATES, ANY STATE OR POLITICAL SUBDIVISION THEREOF, ANY FOREIGN
GOVERNMENT, ANY INTERNATIONAL ORGANIZATION, OR ANY AGENCY OR INSTRUMENTALITY OF ANY OF THE FOREGOING, (B) ANY ORGANIZATION (OTHER
THAN A COOPERATIVE DESCRIBED IN SECTION 521 OF THE CODE) WHICH IS EXEMPT FROM THE TAX IMPOSED BY CHAPTER 1 OF THE CODE UNLESS SUCH
ORGANIZATION IS SUBJECT TO THE TAX IMPOSED BY SECTION 511 OF THE CODE, (C) ANY ORGANIZATION DESCRIBED IN SECTION 1381(a)(2)(C) OF
THE CODE (ANY SUCH PERSON DESCRIBED IN THE FOREGOING CLAUSES (A), (B), OR (C) BEING HEREINAFTER REFERRED TO AS A
“DISQUALIFIED ORGANIZATION”), OR (D) AN AGENT OF A DISQUALIFIED ORGANIZATION AND (2) NO PURPOSE OF SUCH TRANSFER IS TO
ENABLE THE TRANSFEROR TO IMPEDE THE ASSESSMENT OR COLLECTION OF TAX. SUCH AFFIDAVIT SHALL INCLUDE CERTAIN REPRESENTATIONS AS TO THE
FINANCIAL CONDITION OF THE PROPOSED TRANSFEREE. NOTWITHSTANDING THE REGISTRATION IN THE CERTIFICATE REGISTER OF ANY TRANSFER, SALE
OR OTHER DISPOSITION OF THIS CLASS R CERTIFICATE TO A DISQUALIFIED ORGANIZATION OR AN AGENT OF A DISQUALIFIED ORGANIZATION, SUCH
REGISTRATION SHALL BE DEEMED TO BE OF NO LEGAL FORCE OR EFFECT WHATSOEVER AND SUCH PERSON SHALL NOT BE DEEMED TO BE A
CERTIFICATEHOLDER FOR ANY PURPOSE HEREUNDER, INCLUDING, BUT NOT LIMITED TO, THE RECEIPT OF DISTRIBUTIONS ON THIS CERTIFICATE. EACH
HOLDER OF THE CLASS R CERTIFICATE BY ACCEPTANCE OF THIS CERTIFICATE SHALL BE DEEMED TO HAVE CONSENTED TO THE PROVISIONS OF THIS
PARAGRAPH.


(vii)      The Tax Matters Person for each of REMIC I and REMIC II, while not a Disqualified
Organization, shall be the tax matters person for the related REMIC within the meaning of Section 6231(a)(7) of the Code and
Treasury Regulation Section 1.860F-4(d).


(d)        In the case of any
Junior Subordinate Certificate presented for registration in the name of any Person, the Trustee shall require (i) an
officer’s certificate substantially in the form of Exhibit N attached hereto acceptable to and in form and substance
satisfactory to the Trustee and the Company, which officer’s certificate shall not be an expense of the Trust, the Trustee,
the Master Servicer or the Company and (ii) only if such officer’s certificate indicates that a Benefit Plan Opinion is
delivered in connection therewith, a Benefit Plan Opinion.


In the case of any Residual Certificate presented for registration in
the name of any Person, the Trustee shall require (i) a Transferee Affidavit and Agreement which includes the representation set
forth in paragraph 19 of the form attached hereto as Exhibit J and (ii) only if the representation set forth in such paragraph 19
indicates that a Benefit Plan Opinion is delivered in connection therewith, a Benefit Plan Opinion.


In the case of any Class Y Certificate presented for registration in
the name of any Person, the Trustee shall require (i) an officer’s certificate substantially in the form of Exhibit P
attached hereto acceptable to and in form and substance satisfactory to the Trustee and the Company, which officer’s
certificate shall not be an expense of the Trust, the Trustee, the Master Servicer or the Company, and (ii) only if such
officer’s certificate indicates that a Benefit Plan Opinion is delivered in connection therewith, a Benefit Plan
Opinion.


(e)        No transfer, sale,
pledge or other disposition of a Junior Subordinate Certificate shall be made unless such transfer, sale, pledge or other
disposition is made in accordance with this Section 5.01(e) or Section 5.01(f).  Each Person who, at any time, acquires any
ownership interest in any Junior Subordinate Certificate shall be deemed by the acceptance or acquisition of such ownership
interest to have agreed to be bound by the following provisions of this Section 5.01(e) and Section 5.01(f), as applicable. 
No transfer of a Junior Subordinate Certificate shall be deemed to be made in accordance with this Section 5.01(e) unless such
transfer is made pursuant to an effective registration statement under the Securities Act or unless the Trustee is provided with
the certificates and an Opinion of Counsel, if required, on which the Trustee may conclusively rely, to the effect that such
transfer is exempt from the registration requirements under the Securities Act, as follows:  In the event that a transfer is
to be made in reliance upon an exemption from the Securities Act, the Trustee shall require, in order to assure compliance with the
Securities Act, that the Certificateholder desiring to effect such transfer certify to the Trustee in writing, in substantially the
form attached hereto as Exhibit F, the facts surrounding the transfer, with such modifications to such Exhibit F as may be
appropriate to reflect the actual facts of the proposed transfer, and that the Certificateholder’s proposed transferee
certify to the Trustee in writing, in substantially the form attached hereto as Exhibit G, the facts surrounding the transfer, with
such modifications to such Exhibit G as may be appropriate to reflect the actual facts of the proposed transfer. If such
certificate of the proposed transferee does not contain substantially the substance of Exhibit G, the Trustee shall require an
Opinion of Counsel that such transfer may be made without registration, which Opinion of Counsel shall not be obtained at the
expense of the Trustee, the Trust or the Company. Such Opinion of Counsel shall allow for the forwarding, and the Trustee shall
forward, a copy thereof to the Rating Agencies. Notwithstanding the foregoing, any Junior Subordinate Certificate may be
transferred, sold, pledged or otherwise disposed of in accordance with the requirements set forth in Section 5.01(f).


(f)         To effectuate a
Certificate transfer of a Junior Subordinate Certificate in accordance with this Section 5.01(f), the proposed transferee of such
Certificate must provide the Trustee and the Company with an investment letter substantially in the form of Exhibit L attached
hereto, which investment letter shall not be an expense of the Trust, the Trustee or the Company, and which investment letter
states that, among other things, such transferee (i) is a “qualified institutional buyer” as defined under Rule 144A,
acting for its own account or the accounts of other “qualified institutional buyers” as defined under Rule 144A, and
(ii) is aware that the proposed transferor intends to rely on the exemption from registration requirements under the Securities Act
provided by Rule 144A. Notwithstanding the foregoing, the proposed transferee of such Certificate shall not be required to provide
the Trustee or the Company with Annex 1 or Annex 2 to the form of Exhibit L attached hereto if the Company so consents prior to
each such transfer. Such transfers shall be deemed to have complied with the requirements of this Section 5.01(f). The Holder of a
Certificate desiring to effect such transfer does hereby agree to indemnify the Trust, the Trustee, the Company, and the
Certificate Registrar against any liability that may result if transfer is not made in accordance with this Agreement.


(g)       
(1)        In the case of any ERISA Restricted Certificate presented for registration in the
name of any Person, the prospective transferee shall be required to provide the Trustee and the Company (A) an officer’s
certificate substantially in the form of Exhibit O attached hereto acceptable to and in form and substance satisfactory to the
Trustee and the Company, which officer’s certificate shall not be an expense of the Trust, the Trustee, the Delaware Trustee,
the Master Servicer or the Company, and (B) only if such officer’s certificate indicates that a Benefit Plan Opinion is
delivered in connection therewith, a Benefit Plan Opinion.


(2)       
Notwithstanding the foregoing, a certification (and, if applicable, a Benefit Plan Opinion) as described in Section 5.01(g)(1)
above will not be required with respect to the transfer of any ERISA Restricted Certificate to a Clearing Agency, or for any
subsequent transfer of any interest in a ERISA Restricted Certificate for so long as such Certificate is a Book-Entry Certificate
(each such ERISA Restricted Certificate, a “Book-Entry ERISA Restricted Certificate”).  Any transferee of a
Book-Entry ERISA Restricted Certificate will be deemed to have represented, by virtue of its acquisition or holding of such
Certificate (or interest therein), that either (i) such transferee is not an employee benefit or other plan subject to the
prohibited transaction provisions of ERISA or Section 4975 of the Code, or any person (including an investment manager, a named
fiduciary or a trustee of any such plan) acting, directly or indirectly, on behalf of or purchasing such Certificate with
“plan assets” of any such plan (a “Plan Investor”), (ii) such transferee is an insurance company,
the source of funds to be used by it to acquire or hold such Certificate is an “insurance company general account”
(within the meaning of Department of Labor Prohibited Transaction Class Exemption (“PTCE”) 95-60), and the
conditions in Sections I and III of PTCE 95-60 have been satisfied (each entity that satisfies this clause (ii), a
“Complying Insurance Company”) or (iii) such Certificate was rated “BBB-” or better (or its
equivalent) by at least one of the Rating Agencies at the time of such transferee’s acquisition of such Certificate (or
interest therein).


(3)       
If any Book-Entry ERISA Restricted Certificate (or any interest therein) is acquired or held in violation of the provisions of
Section 5.01(g)(2) above, then the last preceding transferee that either (i) is not a Plan Investor, (ii) is a Complying Insurance
Company or (iii) acquired such Certificate at a time when such Certificate was rated “BBB-” or better (or its
equivalent) by at least one of the Rating Agencies shall be restored, to the extent permitted by law, to all rights and obligations
as Beneficial Holder thereof retroactive to the date of transfer of such Certificate by such preceding transferee.  Neither
the Trust nor the Trustee shall be under any liability to any Person for making any payments due on such Certificate to such
preceding transferee.


(4)       
Any purported Beneficial Holder whose acquisition or holding of any Book-Entry ERISA Restricted Certificate (or interest therein)
was effected in violation of the restrictions in this Section 5.01(g) shall indemnify and hold harmless the Company, the Trustee,
the Delaware Trustee, the Master Servicer, the Trust and the Underwriters from and against any and all liabilities, claims, costs
or expenses incurred by such parties as a result of such acquisition or holding.


Section
5.02.        Certificates Issuable in Classes; Distributions of Principal and Interest; Authorized
Denominations. The aggregate principal amount of the Certificates that
may be authenticated and delivered under this Agreement is limited to the aggregate Principal Balance of the Mortgage Loans as of
the Cut-Off Date, as specified in the Preliminary Statement to this Agreement, except for Certificates authenticated and delivered
upon registration of transfer of, or in exchange for, or in lieu of, other Certificates pursuant to Section 5.03. Such aggregate
principal amount shall be allocated among one or more Classes having designations, types of interests, initial per annum
Certificate Interest Rates, initial Class Principal Balances and Final Maturity Dates as specified in the Preliminary Statement to
this Agreement. The aggregate Percentage Interest of each Class of Certificates of which the Class Principal Balance equals zero as
of the Cut-Off Date that may be authenticated and delivered under this Agreement is limited to 100%. Certificates shall be issued
in Authorized Denominations.


Section
5.03.        Registration of Transfer and Exchange of Certificates. The Trustee shall cause to be maintained at one of its offices or at its designated agent, a Certificate Register in
which there shall be recorded the name and address of each Certificateholder. Subject to such reasonable rules and regulations as
the Trustee may prescribe, the Certificate Register shall be amended from time to time by the Trustee or its agent to reflect
notice of any changes received by the Trustee or its agent pursuant to Section 10.06. The Trustee hereby appoints itself as the
initial Certificate Registrar.


Upon surrender for registration of transfer of any Certificate to the
Trustee at the office of the Trustee’s agent at DTC Transfer Agent Services, 55 Water Street, Jeanette Park Entrance, New
York, New York 10041, or at DB Services Tennessee, Inc., 648 Grassmere Park Road, Nashville, TN 37211, Attention: Transfer
Department, or such other address or agency as may hereafter be provided to the Master Servicer in writing by the Trustee, the
Trustee shall execute, and the Trustee or any Authenticating Agent shall authenticate and deliver, in the name of the designated
transferee or transferees, one or more new Certificates of Authorized Denominations. At the option of the Certificateholders,
Certificates may be exchanged for other Certificates in Authorized Denominations of like Certificate Principal Balance or
Percentage Interest, as applicable, upon surrender of the Certificates to be exchanged at any such office or agency. Whenever any
Certificates are so surrendered for exchange, the Trustee on behalf of the Trust shall execute, and the Trustee, or any
Authenticating Agent, shall authenticate and deliver, the Certificates which the Certificateholder making the exchange is entitled
to receive. Every Certificate presented or surrendered for transfer shall (if so required by the Trustee or any Authenticating
Agent) be duly endorsed by, or be accompanied by a written instrument of transfer in form satisfactory to the Trustee or any
Authenticating Agent and duly executed by, the Holder thereof or such Holder’s attorney duly authorized in
writing.


A reasonable service charge may be made for any such exchange or
transfer of Certificates, and the Trustee may require payment of a sum sufficient to cover any tax or governmental charge that may
be imposed in connection with any exchange or transfer of Certificates.


All Certificates surrendered for exchange or transfer shall be
cancelled by the Trustee or any Authenticating Agent.


Section
5.04.        Mutilated, Destroyed, Lost or Stolen Certificates. If (i) any mutilated Certificate is surrendered to the Trustee or any Authenticating Agent, or (ii) the Trustee or any
Authenticating Agent receives evidence to their satisfaction of the destruction, loss or theft of any Certificate, and there is
delivered to the Trustee or any Authenticating Agent such security or indemnity as may be required by them to save each of them and
the Trust harmless, then, in the absence of notice to the Trustee or any Authenticating Agent that such Certificate has been
acquired by a protected purchaser, the Trustee shall execute and the Trustee or any Authenticating Agent shall authenticate and
deliver, in exchange for or in lieu of any such mutilated, destroyed, lost or stolen Certificate, a new Certificate of like
Certificate Principal Balance or Percentage Interest as applicable. Upon the issuance of any new Certificate under this Section
5.04, the Trustee or any Authenticating Agent may require the payment of a sum sufficient to cover any tax or other governmental
charge that may be imposed in relation thereto and any other expenses (including the fees and expenses of the Trustee or any
Authenticating Agent) connected therewith. Any replacement Certificate issued pursuant to this Section 5.04 shall constitute
complete and indefeasible evidence of ownership in REMIC II (or with respect to the Class R Certificates, the residual ownership
interests in REMIC I and REMIC II) as if originally issued, whether or not the lost or stolen Certificate shall be found at any
time.


Section
5.05.        Persons Deemed Owners. The Company, the
Master Servicer, the Trust, the Trustee, the Delaware Trustee and any agent of any of them may treat the Person in whose name any
Certificate is registered as the owner of such Certificate for the purpose of receiving distributions pursuant to Section 4.01 and
Section 4.04 and for all other purposes whatsoever, and neither the Company, the Master Servicer, the Trust, the Trustee, the
Delaware Trustee, the Certificate Registrar nor any agent of the Company, the Master Servicer, the Trust, the Trustee or the
Delaware Trustee shall be affected by notice to the contrary.


Section
5.06.        Temporary Certificates. Upon the initial
issuance of the Certificates, the Trustee on behalf of the Trust may execute, and the Trustee or any Authenticating Agent shall
authenticate and deliver, temporary Certificates which are printed, lithographed, typewritten or otherwise produced, in any
Authorized Denomination, of the tenor of the definitive Certificates in lieu of which they are issued and with such variations in
form from the forms of the Certificates set forth as Exhibits A, B and H hereto as the Trustee’s officers executing such
Certificates may determine, as evidenced by their execution of the Certificates.  Notwithstanding the foregoing, the
Certificates may remain in the form of temporary Certificates.


If temporary Certificates are issued, the Trustee shall cause
definitive Certificates to be prepared within ten Business Days after the Closing Date or as soon as practicable thereafter. After
preparation of definitive Certificates, the temporary Certificates shall be exchangeable for definitive Certificates upon surrender
of the temporary Certificates at the office or agency of the Trustee to be maintained as provided in Section 5.10 hereof, without
charge to the holder. Any tax or governmental charge that may be imposed in connection with any such exchange shall be borne by the
Master Servicer. Upon surrender for cancellation of any one or more temporary Certificates, the Trustee on behalf of the Trust
shall execute and the Trustee or any Authenticating Agent shall authenticate and deliver in exchange therefor a like principal
amount of definitive Certificates of Authorized Denominations. Until so exchanged, the temporary Certificates shall in all respects
be entitled to the same benefits under this Agreement as definitive Certificates.


Section
5.07.        Book-Entry for Book-Entry Certificates.
Notwithstanding the foregoing, the Book-Entry Certificates, upon original issuance, shall be issued in the form of one or more
typewritten Certificates of Authorized Denomination representing the Book-Entry Certificates, to be delivered to DTC, the initial
Clearing Agency, by, or on behalf of, the Company.  The Book-Entry Certificates shall initially be registered on the
Certificate Register in the name of Cede & Co., the nominee of DTC, as the initial Clearing Agency, and no Beneficial Holder
shall receive a definitive certificate representing such Beneficial Holder’s interest in any Class of Book-Entry Certificate,
except as provided above and in Section 5.09.  Each Book-Entry Certificate shall bear the following legend:


Unless this Certificate is presented by an authorized representative of The Depository Trust Company, a
New York corporation (“DTC”), to the Company or its agent for registration of transfer, exchange, or payment,
and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by an authorized
representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized
representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as
the registered owner hereof, Cede & Co., has an interest herein.


Unless and until definitive, fully registered Book-Entry
Certificates (the “Definitive Certificates”) have been issued to the Beneficial Holders pursuant to Section
5.09:


(a)       
the provisions of this Section 5.07 shall be in full force and effect with respect to the Book-Entry Certificates;


(b)       
the Master Servicer and the Trustee may deal with the Clearing Agency for all purposes with respect to the Book-Entry Certificates
(including the making of distributions on the Book-Entry Certificates) as the sole Certificateholder;


(c)       
to the extent that the provisions of this Section 5.07 conflict with any other provisions of this Agreement, the provisions of this
Section 5.07 shall control; and


(d)       
the rights of the Beneficial Holders shall be exercised only through the Clearing Agency and the DTC Participants and shall be
limited to those established by law and agreements between such Beneficial Holders and the Clearing Agency and/or the DTC
Participants. Pursuant to the Depositary Agreement, unless and until Definitive Certificates are issued pursuant to Section 5.09,
the initial Clearing Agency will make book-entry transfers among the DTC Participants and receive and transmit distributions of
principal and interest on the related Class of Book-Entry Certificates to such DTC Participants.


For purposes of any provision of this Agreement requiring or
permitting actions with the consent of, or at the direction of, Holders of Book-Entry Certificates evidencing a specified
Percentage Interest, such direction or consent may be given by the Clearing Agency at the direction of Beneficial Holders owning
Book-Entry Certificates evidencing the requisite Percentage Interest represented by the Book-Entry Certificates. The Clearing
Agency may take conflicting actions with respect to the Book-Entry Certificates to the extent that such actions are taken on behalf
of the Beneficial Holders.


Section
5.08.        Notices to Clearing Agency. Whenever
notice or other communication to the Certificateholders is required under this Agreement, unless and until Definitive Certificates
shall have been issued to the related Certificateholders pursuant to Section 5.09, the Trustee shall give all such notices and
communications specified herein to be given to Holders of the Book-Entry Certificates to the Clearing Agency which shall give such
notices and communications to the related DTC Participants in accordance with its applicable rules, regulations and
procedures.


Section
5.09.        Definitive Certificates. If (a) the
Clearing Agency or the Master Servicer notifies the Trustee in writing that the Clearing Agency is no longer willing or able to
discharge properly its responsibilities under the Depositary Agreement with respect to the Book-Entry Certificates and the Trustee
or the Master Servicer is unable to locate a qualified successor, (b) the Master Servicer, with the consent of the related DTC
Participants, advises the Trustee in writing that it elects to terminate the book-entry system with respect to the Book-Entry
Certificates through the Clearing Agency or (c) after the occurrence of an Event of Default, Certificateholders holding Book-Entry
Certificates evidencing Percentage Interests aggregating not less than 662⁄3% of the aggregate Class Principal Balance of such
Certificates advise the Trustee and the Clearing Agency through DTC Participants in writing that the continuation of a book-entry
system with respect to the Book-Entry Certificates through the Clearing Agency is no longer in the best interests of the
Certificateholders with respect to such Certificates, the Trustee shall notify all Certificateholders of Book-Entry Certificates of
the occurrence of any such event and of the availability of Definitive Certificates.  Upon surrender to the Trustee of the
Book-Entry Certificates by the Clearing Agency, accompanied by registration instructions from the Clearing Agency for registration,
the Trustee on behalf of the Trust shall execute and the Trustee or any Authenticating Agent shall authenticate and deliver the
Definitive Certificates.  Neither the Company, the Master Servicer, the Trust nor the Trustee shall be liable for any delay in
delivery of such instructions and may conclusively rely on, and shall be protected in relying on, such instructions.  Upon the
issuance of Definitive Certificates for all of the Certificates all references herein to obligations imposed upon or to be
performed by the Clearing Agency shall be deemed to be imposed upon and performed by the Trustee, to the extent applicable with
respect to such Definitive Certificates, and the Trustee shall recognize the Holders of Definitive Certificates as
Certificateholders hereunder.


Section 5.10.        Office for Transfer of Certificates. The Trustee shall
maintain in New York, New York an office or agency where Certificates may be surrendered for registration of transfer or exchange.
The office of the Trustee’s agent at DTC Transfer Agent Services, 55 Water Street, Jeanette Park Entrance, New York, New York
10041, is initially designated for said purposes.


Section
5.11.        Nature of Certificates. The Certificates
shall be personal property giving only the rights specifically set forth therein and in this Agreement.  The Certificates
shall have no preemptive or similar rights and when issued and delivered to the Holders against payment of the purchase price
therefor will be fully paid and nonassessable by the Trust.  The Holders of the Certificates, in their capacities as such,
shall be entitled to the same limitation of personal liability extended to stockholders of private corporations for profit
organized under the General Corporation Law of the State of Delaware. THE RECEIPT AND ACCEPTANCE OF A CERTIFICATE OR ANY INTEREST
THEREIN BY OR ON BEHALF OF A HOLDER OR ANY BENEFICIAL OWNER, WITHOUT ANY SIGNATURE OR FURTHER MANIFESTATION OF ASSENT, SHALL
CONSTITUTE THE UNCONDITIONAL ACCEPTANCE BY THE HOLDER AND ALL OTHERS HAVING A BENEFICIAL INTEREST IN SUCH CERTIFICATE OF ALL THE
TERMS AND PROVISIONS OF THIS AGREEMENT, AND SHALL CONSTITUTE THE AGREEMENT OF THE TRUST, SUCH HOLDER AND SUCH OTHERS THAT THE TERMS
AND PROVISIONS OF THIS AGREEMENT SHALL BE BINDING, OPERATIVE AND EFFECTIVE AS BETWEEN THE TRUST AND SUCH HOLDER AND SUCH
OTHERS.


ARTICLE VI



The Company and the Master Servicer


Section
6.01.        Liability of the Company and the Master Servicer. The Company and the Master Servicer shall be liable in accordance herewith only to the extent of the obligations
specifically imposed upon and undertaken by the Company or the Master Servicer, as applicable, herein.


Section
6.02.        Merger or Consolidation of the Company, or the Master Servicer. Any Corporation into which the Company or the Master Servicer may be merged or consolidated, or any
Corporation resulting from any merger, conversion or consolidation to which the Company or the Master Servicer shall be a party, or
any Corporation succeeding to the business of the Company or the Master Servicer, shall be the successor of the Company or the
Master Servicer hereunder, without the execution or filing of any paper or any further act on the part of any of the parties
hereto, anything herein to the contrary notwithstanding.


Section
6.03.        Limitation on Liability of the Company, the Master Servicer and Others. Neither the Company nor the Master Servicer nor any of the directors, officers, employees or
agents of the Company or the Master Servicer shall be under any liability to the Trust, the Holders of the REMIC I Regular
Interests or the Certificateholders for any action taken by such Person or by a Servicer or for such Person's or Servicer's
refraining from the taking of any action in good faith pursuant to this Agreement, or for errors in judgment; provided,
however, that this provision shall not protect the Company, the Master Servicer or any such Person against any liability which
would otherwise be imposed by reason of willful misfeasance, bad faith or gross negligence in the performance of duties or by
reason of reckless disregard of duties and obligations hereunder. The Company, the Master Servicer and any director, officer,
employee or agent of the Company or the Master Servicer may rely in good faith on any document of any kind properly executed and
submitted by any Person respecting any matters arising hereunder. The Company, the Master Servicer and any director, officer,
employee or agent of the Company or the Master Servicer shall be indemnified by the Trust and held harmless against any loss,
liability or expense incurred in connection with any legal action relating to this Agreement or the Certificates, other than any
loss, liability or expense relating to any Mortgage Loan (other than as otherwise permitted in this Agreement) or incurred by
reason of willful misfeasance, bad faith or gross negligence in the performance of duties hereunder or by reason of reckless
disregard of obligations and duties hereunder. The Company and the Master Servicer shall not be under any obligation to appear in,
prosecute or defend any legal action which is not incidental to its duties to service the Mortgage Loans in accordance with this
Agreement and which in its opinion may involve it in any expense or liability; provided, however, that the Company or the
Master Servicer may in its discretion undertake any such action which it may deem necessary or desirable with respect to the
Mortgage Loans, this Agreement, the Certificates or the rights and duties of the parties hereto and the interests of the
Certificateholders hereunder. In such event, the legal expenses and costs of such action and any liability resulting therefrom
shall be expenses, costs and liabilities of the Trust and the Company and the Master Servicer shall be entitled to be reimbursed
therefor out of the Certificate Account, as provided by Section 3.05.


Section
6.04.        The Company and the Master Servicer not to Resign. The Company shall not resign from the obligations and duties (including, without limitation, its obligations and duties as
initial Master Servicer) hereby imposed on it except upon determination that its duties hereunder are no longer permissible under
applicable law. Any successor Master Servicer shall not resign from the obligations and duties hereby imposed on it except upon
determination that its duties hereunder are no longer permissible under applicable law. Any such determination permitting the
resignation of the Company or any successor Master Servicer shall be evidenced by an Opinion of Counsel to such effect delivered to
the Trustee. No such resignation shall become effective until the Trustee or a successor Master Servicer shall have assumed the
Master Servicer's responsibilities and obligations in accordance with Section 7.02 hereof.


If the Company is no longer acting as Master Servicer, then the
successor Master Servicer shall give prompt written notice to the Company of any information received by such successor Master
Servicer which affects or relates to an ongoing obligation or right of the Company under this Agreement.


Section
6.05.        Trustee Access. The Master Servicer shall afford the Company and the Trustee, upon reasonable notice, during normal business hours
access to all records maintained by the Master Servicer, in respect of the Mortgage Loans and in respect of its rights and
obligations hereunder and access to such of its officers as are responsible for such obligations.  Upon reasonable request,
the Master Servicer, shall furnish the Company and the Trustee with its most recent financial statements (or, for so long as the
Company is the Master Servicer, the most recent consolidated financial statements for the Company appearing in the audited
financial statements of Washington Mutual, Inc., or the entity with whose financial statements the financial statements of the
Company are consolidated) and such other information as it possesses, and which it is not prohibited by law or, to the extent
applicable, binding obligations to third parties with respect to confidentiality from disclosing, regarding its business, affairs,
property and condition, financial or otherwise.


ARTICLE VII



Default 


Section
7.01.        Events of Default. (a) In case one or more
of the following Events of Default by the Master Servicer or by a successor Master Servicer shall occur and be continuing, that is
to say:


(i)                  Any
failure by the Master Servicer to deposit into the Certificate Account any payment required to be deposited therein by the Master
Servicer under the terms of this Agreement which continues unremedied for a period of five Business Days after the date upon which
written notice of such failure, requiring the same to be remedied, shall have been given to the Master Servicer by the Trustee or
to the Master Servicer and the Trustee by the Holders of Certificates evidencing Percentage Interests aggregating not less than 25%
of REMIC II; or


(ii)                Failure on the
part of the Master Servicer duly to observe or perform in any material respect any other of the covenants or agreements on the part
of the Master Servicer contained in the Certificates or in this Agreement which continues unremedied for a period of 60 days after
the date on which written notice of such failure, requiring the same to be remedied, shall have been given to the Master Servicer
by the Trustee, or to the Master Servicer and the Trustee by the Holders of Certificates evidencing Percentage Interests
aggregating not less than 25% of REMIC II; or


(iii)               A decree or order of a
court or agency or supervisory authority having jurisdiction in the premises for the appointment of a trustee in bankruptcy,
conservator or receiver or liquidator in any bankruptcy, insolvency, readjustment of debt, marshalling of assets and liabilities or
similar proceedings, or for the winding‐up or liquidation of its affairs, shall have been entered against the Master Servicer
and such decree or order shall have remained in force undischarged or unstayed for a period of 60 days; or


(iv)              The Master Servicer shall
consent to the appointment of a trustee in bankruptcy, conservator or receiver or liquidator in any bankruptcy, insolvency,
readjustment of debt, marshalling of assets and liabilities or similar proceedings of or relating to the Master Servicer or of or
relating to all or substantially all of its property; or


(v)                The Master
Servicer shall admit in writing its inability to pay its debts generally as they become due, file a petition to take advantage of
any applicable bankruptcy, insolvency or reorganization statute, make an assignment for the benefit of its creditors, or
voluntarily suspend payment of its obligations; or


(vi)              Any failure of the Master
Servicer to make any Monthly P&I Advance (other than a Nonrecoverable Advance) which continues unremedied at the opening of
business on the Distribution Date in respect of which such Monthly P&I Advance was to have been made;


then, and in each and every such case, so long as an Event of
Default shall not have been remedied, either the Trustee or the Holders of Certificates evidencing Percentage Interests aggregating
not less than 25% of REMIC II, by notice in writing to the Company and the Master Servicer (and to the Trustee if given by the
Certificateholders, in which case such notice shall set forth evidence reasonably satisfactory to the Trustee that such Event of
Default has occurred and shall not have been remedied) may terminate all of the rights (other than its right to reimbursement for
advances) and obligations of the Master Servicer, including its right to the Master Servicing Fee, under this Agreement and in and
to the Mortgage Loans and the proceeds thereof, if any. Such determination shall be final and binding. On or after the receipt by
the Master Servicer of such written notice, all authority and power of the Master Servicer under this Agreement, whether with
respect to the Certificates or the Mortgage Loans or otherwise, shall pass to and be vested in the Trustee pursuant to and under
this Section 7.01; and, without limitation, the Trustee is hereby authorized and empowered to execute and deliver, on behalf of the
Master Servicer, as attorney‐in‐fact or otherwise, any and all documents and other instruments, and to do or accomplish
all other acts or things necessary or appropriate to effect the purposes of such notice of termination, whether to complete the
transfer and endorsement or assignment of the Mortgage Loans and related documents, or otherwise. The Master Servicer agrees to
cooperate with the Trustee in effecting the termination of the Master Servicer's responsibilities and rights hereunder, including,
without limitation, the transfer to the Trustee for administration by it of all cash amounts which shall at the time be credited by
the Master Servicer to the Certificate Account or thereafter be received with respect to the Mortgage Loans.


Notwithstanding the foregoing, if an Event of Default described in
clause (vi) of this Section 7.01(a) shall occur, the Trustee shall, by notice in writing to the Master Servicer, which may be
delivered by telecopy, immediately suspend all of the rights and obligations of the Master Servicer thereafter arising under this
Agreement, but without prejudice to any rights it may have as a Certificateholder or to reimbursement of Monthly P&I Advances
and other advances of its own funds, and the Trustee shall act as provided in Section 7.02 to carry out the duties of the Master
Servicer, including the obligation to make any Monthly P&I Advance the nonpayment of which was an Event of Default described in
clause (vi) of this Section 7.01(a). Any such action taken by the Trustee must be prior to the distribution on the relevant
Distribution Date. If the Master Servicer shall within two Business Days following such suspension remit to the Trustee the amount
of any Monthly P&I Advance the nonpayment of which by the Master Servicer was an Event of Default described in clause (vi)
of this Section 7.01(a), the Trustee, subject to the last sentence of this paragraph, shall permit the Master Servicer to
resume its rights and obligations as Master Servicer hereunder. The Master Servicer agrees that it will reimburse the Trustee for
actual, necessary and reasonable costs incurred by the Trustee because of action taken pursuant to clause (vi) of this Section
7.01(a). The Master Servicer agrees that if an Event of Default as described in clause (vi) of this Section 7.01(a) shall occur
more than two times in any twelve month period, the Trustee shall be under no obligation to permit the Master Servicer to resume
its rights and obligations as Master Servicer hereunder.


(b)        In case one or more of
the following Events of Default by the Company shall occur and be continuing, that is to say:


(i)         Failure on the part of the Company duly to observe or perform in any
material respect any of the covenants or agreements on the part of the Company contained in the Certificates or in this Agreement
which continues unremedied for a period of 60 days after the date on which written notice of such failure, requiring the same to be
remedied, shall have been given to the Company by the Trustee, or to the Company and the Trustee by the Holders of Certificates
evidencing Percentage Interests aggregating not less than 25% of REMIC II; or


(ii)        A decree or order of a court or agency or supervisory authority having
jurisdiction in the premises for the appointment of a trustee in bankruptcy, conservator or receiver or liquidator in any
bankruptcy, insolvency, readjustment of debt, marshalling of assets and liabilities or similar proceedings, or for the
winding‐up or liquidation of its affairs, shall have been entered against the Company and such decree or order shall have
remained in force undischarged or unstayed for a period of 60 days; or


(iii)       The Company shall consent to the appointment of a trustee in bankruptcy,
conservator or receiver or liquidator in any bankruptcy, insolvency, readjustment of debt, marshalling of assets and liabilities or
similar proceedings of or relating to the Company or of or relating to all or substantially all of its property; or


(iv)       The Company shall admit in writing its inability to pay its debts generally as they
become due, file a petition to take advantage of any applicable bankruptcy, insolvency or reorganization statute, make an
assignment for the benefit of creditors, or voluntarily suspend payment of its obligations;


then, and in each and every such case, so long as such Event of
Default shall not have been remedied, the Holders of Certificates evidencing Percentage Interests aggregating not less than 25% of
REMIC II, by notice in writing to the Company and the Trustee, may direct the Trustee in accordance with Section 10.03 to institute
an action, suit or proceeding in its own name as Trustee hereunder to enforce the Company's obligations hereunder.


(c)        In any circumstances in
which this Agreement states that Certificateholders owning Certificates evidencing a certain Percentage Interest in REMIC II may
take certain action, such action shall be taken by the Trustee, but only if the requisite percentage of Certificateholders required
under this Agreement for taking like action or giving like instruction to the Trustee under this Agreement shall have so directed
the Trustee in writing.


Section
7.02.        Trustee to Act; Appointment of Successor.


(a)        On and after the date on
which the Master Servicer receives a notice of termination pursuant to Section 7.01 or the Master Servicer resigns pursuant to
Section 6.04, the Trustee shall be the successor in all respects to the Master Servicer under this Agreement and under the Selling
and Servicing Contracts with respect to the Mortgage Loans in the Mortgage Pool and with respect to the transactions set forth or
provided for herein and shall have all the rights and powers and be subject to all the responsibilities, duties and liabilities
relating thereto arising on or after such date of termination or resignation placed on the Master Servicer by the terms and
provisions hereof and thereof, and shall have the same limitations on liability herein granted to the Master Servicer;
provided, that the Trustee shall not under any circumstances be responsible for any representations and warranties or any
Purchase Obligation of the Company or any liability incurred by the Master Servicer prior to such date of termination or
resignation and the Trustee shall not be obligated to make a Monthly P&I Advance if it is prohibited by law from so doing. As
compensation therefor, the Trustee shall be entitled to all funds relating to the Mortgage Loans which the Master Servicer would
have been entitled to retain or to withdraw from the Certificate Account if the Master Servicer had continued to act hereunder,
except for those amounts due to the Master Servicer as reimbursement for advances previously made or amounts previously expended
and are otherwise reimbursable hereunder. Notwithstanding the above, the Trustee may, if it shall be unwilling to so act, or shall
if it is unable to so act, appoint, or petition a court of competent jurisdiction to appoint, any established housing and home
finance institution having a net worth of not less than $10,000,000 as the successor to the Master Servicer hereunder in the
assumption of all or any part of the responsibilities, duties or liabilities of the Master Servicer hereunder. Pending any such
appointment, the Trustee is obligated to act in such capacity. In connection with such appointment and assumption, the Trustee may
make such arrangements for the compensation of such successor out of payments on Mortgage Loans as it and such successor shall
agree; provided, however, that no such compensation shall, together with the compensation to the Trustee, be in excess of
that permitted the Master Servicer hereunder. The Trustee and such successor shall take such actions, consistent with this
Agreement, as shall be necessary to effectuate any such succession.


(b)        In connection with any
termination or resignation of the Master Servicer hereunder, in the event that any of the Mortgage Loans are MERS Loans, either (i)
the successor Master Servicer (including the Trustee if the Trustee is acting as successor Master Servicer) shall represent and
warrant that it is a member of MERS in good standing and shall agree to comply in all material respects with the rules and
procedures of MERS in connection with the servicing of the MERS Loans, in which case the predecessor Master Servicer shall
cooperate with the successor Master Servicer in registering the transfer of servicing of the MERS Loans to the successor Master
Servicer on the MERS® System in accordance with MERS’ rules and procedures, or (ii) if the successor Master Servicer is
not a member of MERS, the predecessor Master Servicer shall cooperate with the successor Master Servicer in (A) de-registering the
MERS Loans from the MERS® System and (B) causing MERS to execute and deliver an assignment from MERS to the Trust of the
Mortgage securing each MERS Loan in recordable form and in the form otherwise provided under clause (X)(iii) of the definition of
“Mortgage File” herein and to execute and deliver such other notices, documents and other instruments as may be
necessary or desirable to effect such de-registration and assignment. The predecessor Master Servicer shall bear any and all fees
of MERS and all fees and costs of preparing and recording any assignments of Mortgages as required under this Section
7.02(b).


Section
7.03.        Notification to Certificateholders. Upon
any such termination or appointment of a successor to the Master Servicer, the Trustee shall give prompt written notice thereof to
the Certificateholders at their respective addresses appearing in the Certificate Register.


ARTICLE VIII



Concerning the Trustees 


Section
8.01.        Duties of Trustees.


(a)        The Trustee, prior to
the occurrence of an Event of Default and after the curing of all Events of Default which may have occurred, undertakes to perform
such duties and only such duties as are specifically set forth in this Agreement. In case an Event of Default has occurred (which
has not been cured or waived) the Trustee shall exercise such of the rights and powers vested in it by this Agreement, and use the
same degree of care and skill in its exercise as a prudent person would exercise or use under the circumstances in the conduct of
such person’s own affairs.


(b)        The Trustee, upon
receipt of all resolutions, certificates, statements, opinions, reports, documents, orders or other instruments furnished to it
which are specifically required to be furnished pursuant to any provision of this Agreement, shall examine them to determine
whether they are in the form required by this Agreement; provided, however, that the Trustee shall not be responsible for
the accuracy or content of any such certificate, statement, opinion, report, or other order or instrument furnished by the Company
or Master Servicer to the Trustee pursuant to this Agreement.


(c)        No provision of this
Agreement shall be construed to relieve the Trustee or the Delaware Trustee from liability for its own negligent action, its own
negligent failure to act or its own willful misconduct; provided, however, that:


(i)                  Prior
to the occurrence of an Event of Default and after the curing of all such Events of Default which may have occurred, the duties and
obligations of the Trustee shall be determined solely by the express provisions of this Agreement,


(ii)                Neither the
Trustee nor the Delaware Trustee shall be liable except for the performance of such duties and obligations as are specifically set
forth in this Agreement, no implied covenants or obligations shall be read into this Agreement against the Trustee or the Delaware
Trustee, and, in the absence of bad faith on the part of the Trustee or the Delaware Trustee, such trustee may conclusively rely,
as to the truth of the statements and the correctness of the opinions expressed therein, upon any certificates or opinions
furnished to such trustee and conforming to the requirements of this Agreement; and


(iii)               Neither the Trustee nor
the Delaware Trustee shall be personally liable with respect to any action taken or omitted to be taken by it in good faith in
accordance with the direction of the Certificateholders holding Certificates which evidence Percentage Interests aggregating not
less than 25% of REMIC II relating to the time, method and place of conducting any proceeding for any remedy available to such
trustee, or relating to the exercise of any trust or power conferred upon such trustee under this Agreement.


(d)        Within ten Business Days
after the occurrence of any Event of Default known to the Trustee, the Trustee shall transmit by mail to the Rating Agencies notice
of each Event of Default. Within 90 days after the occurrence of any Event of Default known to the Trustee, the Trustee shall
transmit by mail to all Certificateholders (with a copy to the Rating Agencies) notice of each Event of Default, unless such Event
of Default shall have been cured or waived; provided, however, the Trustee shall be protected in withholding such notice if
and so long as a Responsible Officer of the Trustee in good faith determines that the withholding of such notice is in the best
interests of the Certificateholders; and provided, further, that in the case of any Event of Default of the character specified in
Section 7.01(i) and Section 7.01(ii) no such notice to Certificateholders or to the Rating Agencies shall be given until at least
30 days after the occurrence thereof.


(e)        The immediately
following sentence shall constitute the Trustee's notice required by the U.S. Patriot Act.  In order to comply with its duties
under the U.S. Patriot Act, the Trustee shall obtain and verify certain information and documentation from the other parties to
this Agreement including, but not limited to, each such party’s name, address and other identifying information.


Section
8.02.        Certain Matters Affecting the Trustees.
Except as otherwise provided in Section 8.01:


(i)         Each of the Trustee and the Delaware Trustee may request and rely upon
and shall be protected in acting or refraining from acting upon any resolution, Officer’s Certificate, certificate of
auditors or any other certificate, statement, instrument, opinion, report, notice, request, consent, order, approval, bond or other
paper or document believed by it to be genuine and to have been signed or presented by the proper party or parties;


(ii)        Each of the Trustee and the Delaware Trustee may consult with counsel and any
Opinion of Counsel shall be full and complete authorization and protection in respect of any action taken or suffered or omitted by
it hereunder in good faith and in accordance with such Opinion of Counsel;


(iii)       Neither the Trustee nor the Delaware Trustee shall be personally liable for any
action taken or omitted by it in good faith and reasonably believed by it to be authorized or within the discretion or rights or
powers conferred upon it by this Agreement;


(iv)       Prior to the occurrence of an Event of Default hereunder and after the curing of
all Events of Default which may have occurred, neither the Trustee nor the Delaware Trustee shall be bound to make any
investigation into the facts or matters stated in any resolution, certificate, statement, instrument, opinion, report, notice,
request, consent, order, approval, bond or other paper or document, unless requested in writing to do so by the Holders of
Certificates evidencing Percentage Interests aggregating not less than 25% of REMIC II; provided, however, that if the
payment within a reasonable time to the Trustee or the Delaware Trustee of the costs, expenses or liabilities likely to be incurred
by it in the making of such investigation is, in the opinion of such trustee, not reasonably assured to such trustee by the
security, if any, afforded to it by the terms of this Agreement, such trustee may require reasonable indemnity against such expense
or liability as a condition to proceeding;


(v)        Each of the Trustee and the Delaware Trustee may execute the trust or any of
the powers hereunder or perform any duties hereunder either directly or by or through agents or attorneys selected by it with
reasonable care or (as in the case of the Initial Custodian) designated by the Company;


(vi)       Neither the Trustee nor the Delaware Trustee shall be deemed to have knowledge or
notice of any matter, including without limitation an Event of Default, unless actually known by a Responsible Officer, or unless
written notice thereof referencing this Agreement or the Certificates is received at the Notice Address of such
trustee;


(vii)    In
no event shall the Trustee or the Delaware Trustee be held liable for acts or omissions of the Master Servicer (excepting the
Trustee’s own actions as Master Servicer).   No provision of this Agreement shall require the Trustee or the
Delaware Trustee to expend or risk its own funds or otherwise incur any financial liability in the performance of any of its duties
hereunder (except for the giving of required notices), or in the exercise of any of its rights or powers, if it shall have
reasonable grounds for believing the repayment of such funds or adequate indemnity against such risk or liability is not reasonably
assured to it; and


(viii)      When the Trustee is acting as Master Servicer pursuant to Section 7.02, and to the
extent permitted under applicable law, the Trustee is hereby authorized, in making or disposing of any investment permitted
hereunder, to deal with itself (in its individual capacity) or with any one or more of its affiliates, whether it or its affiliate
is acting as an agent of the Trustee or of any third person or dealing as principal for its own account.


Section
8.03.        Trustees Not Liable for Certificates or Mortgage Loans.  The recitals contained herein (other than those relating to the due organization, power and authority of the
Trustee and the Delaware Trustee) and in the Certificates (other than the execution of, and certificate of authentication on, the
Certificates) shall be taken as the statements of the Company and neither the Trustee nor the Delaware Trustee assumes any
responsibility for their correctness. Neither the Trustee nor the Delaware Trustee makes any representations as to the validity or
sufficiency of this Agreement or of the Certificates or any Mortgage Loan. Neither the Trustee nor the Delaware Trustee shall be
accountable for the use or application by the Company of any of the Certificates or of the proceeds of such Certificates, or for
the use or application of any funds paid to the Master Servicer, the Servicers or the Company in respect of the Mortgage Loans or
deposited into the Custodial Accounts for P&I, any Buydown Fund Account, or the Custodial Accounts for P&I by any Servicer
or into the Investment Account, or the Certificate Account by the Master Servicer or the Company.


Section
8.04.        Trustees May Own Certificates.  The
Trustee, the Delaware Trustee or any agent or affiliate of such trustee, in its individual or any other capacity, may become the
owner or pledgee of Certificates with the same rights it would have if it were not trustee.


Section
8.05.        The Master Servicer to Pay Trustees’ Fees and Expenses.  Subject to separate written agreements with the Trustee and the Delaware Trustee, the Master Servicer
covenants and agrees to, and the Master Servicer shall, pay each of the Trustee and the Delaware Trustee from time to time, and
such trustee shall be entitled to payment, for all services rendered by it in the execution of the trust hereby created and in the
exercise and performance of any of the powers and duties hereunder of such trustee. Except as otherwise expressly provided herein,
the Master Servicer shall pay or reimburse each of the Trustee and the Delaware Trustee upon such trustee’s request for all
reasonable expenses and disbursements incurred or made by such trustee in accordance with any of the provisions of this Agreement
and indemnify such trustee from any loss, liability or expense incurred by it hereunder (including the reasonable compensation and
the expenses and disbursements of its counsel and of all persons not regularly in its employ) except any such expense or
disbursement as may arise from its negligence or bad faith. Such obligation shall survive the termination of this Agreement or
resignation or removal of the Trustee or the Delaware Trustee. The Tax Matters Person shall, at its expense, prepare or cause to be
prepared all federal and state income tax and franchise tax and information returns relating to REMIC I or REMIC II required to be
prepared or filed by the Trustee or the Delaware Trustee and shall indemnify the Trustee and the Delaware Trustee for any liability
of such trustees arising from any error in such returns.


Section
8.06.        Eligibility Requirements for Trustees. The
Trustee hereunder shall at all times be (i) an institution insured by the FDIC, (ii) a Corporation organized and doing business
under the laws of the United States of America or of any state, authorized under such laws to exercise corporate trust powers,
having a combined capital and surplus of not less than $50,000,000 and subject to supervision or examination by federal or state
authority and (iii) acceptable to the Rating Agencies. If such Corporation publishes reports of condition at least annually,
pursuant to law or to the requirements of any aforementioned supervising or examining authority, then for the purposes of this
Section 8.06, the combined capital and surplus of such Corporation shall be deemed to be its combined capital and surplus as set
forth in its most recent report of condition so published.  The Delaware Trustee hereunder shall at all times have its
principal place of business in the State of Delaware and shall satisfy the applicable requirements under the laws of the State of
Delaware authorizing it to act as the Delaware trustee of the Trust.  In case at any time the Trustee or the Delaware Trustee
shall cease to be eligible in accordance with the provisions of this Section 8.06, such trustee shall resign immediately in the
manner and with the effect specified in Section 8.07.


Section
8.07.        Resignation and Removal of Trustees. Each
of the Trustee and the Delaware Trustee may at any time resign and be discharged from the trust hereby created by giving written
notice thereof to the Master Servicer. Upon receiving such notice of resignation, the Master Servicer shall promptly appoint a
successor trustee by written instrument, in duplicate, one copy of which instrument shall be delivered to the resigning trustee and
one copy to the successor trustee. If no successor trustee shall have been so appointed and shall have accepted appointment within
30 days after the giving of such notice of resignation, the resigning trustee may petition any court of competent jurisdiction for
the appointment of a successor trustee.


If at any time the Trustee or the Delaware Trustee shall cease to be
eligible in accordance with the provisions of Section 8.06 and shall fail to resign after written request therefor by the Master
Servicer, or if at any time the Trustee or the Delaware Trustee shall become incapable of acting, or shall be adjudged bankrupt or
insolvent, or a receiver of such trustee or of its property shall be appointed, or any public officer shall take charge or control
of such trustee or of its property or affairs for the purpose of rehabilitation, conservation or liquidation, then the Master
Servicer may remove such trustee and appoint a successor trustee by written instrument, in duplicate, copies of which instrument
shall be delivered to the trustee so removed, the trustee continuing in its capacity and the successor trustee.


The Holders of Certificates evidencing Percentage Interests
aggregating more than 50% of REMIC II may at any time remove the Trustee or the Delaware Trustee and appoint a successor trustee by
written instrument or instruments, in triplicate, signed by such Holders or their attorneys in-fact duly authorized, one complete
set of which instruments shall be delivered to the Master Servicer, one complete set to the Trustee so removed and one complete set
to the successor so appointed.


Any resignation or removal of the Trustee or the Delaware Trustee and
appointment of a successor trustee pursuant to any of the provisions of this Section 8.07 shall become effective upon acceptance of
appointment by the successor trustee as provided in Section 8.08. Any expenses associated with the resignation of the Trustee or
the Delaware Trustee shall be borne by such trustee, and any expenses associated with the removal of the Trustee or the Delaware
Trustee shall be borne by the Master Servicer.


Section
8.08.        Successor Trustee. Any successor trustee
appointed as provided in Section 8.07 shall execute, acknowledge and deliver to the Master Servicer and to its predecessor trustee
an instrument accepting such appointment hereunder, and thereupon the resignation or removal of the predecessor trustee shall
become effective and such successor trustee, without any further act, deed or conveyance, shall become fully vested with all the
rights, powers, duties and obligations of its predecessor hereunder, with like effect as if originally named as Trustee or Delaware
Trustee herein. The predecessor shall deliver to the successor trustee all Mortgage Files, related documents, statements and all
other property held by it hereunder, and the Master Servicer and the predecessor trustee shall execute and deliver such instruments
and do such other things as may reasonably be required for more fully and certainly vesting and confirming in the successor trustee
all such rights, powers, duties and obligations.


No successor trustee shall accept appointment as provided in this
Section 8.08 unless at the time of such appointment such successor trustee shall be eligible under the provisions of Section
8.06.


Upon acceptance of appointment by a successor trustee as provided in
this Section 8.08, the Master Servicer shall mail notice of the succession of such trustee hereunder to (i) all Certificateholders
at their addresses as shown in the Certificate Register and (ii) the Rating Agencies. If the Master Servicer fails to mail such
notice within ten days after acceptance of appointment by the successor trustee, the successor trustee shall cause such notice to
be mailed.


Section
8.09.        Merger or Consolidation of Trustee. Any
Corporation into which the Trustee or the Delaware Trustee may be merged or converted or with which it may be consolidated, or any
Corporation resulting from any merger, conversion or consolidation to which the Trustee or the Delaware Trustee shall be a party,
or any Corporation succeeding to the corporate trust business of such trustee, shall be the successor of such trustee hereunder,
provided such resulting or successor Corporation shall be eligible under the provisions of Section 8.06, without the execution or
filing of any paper or any further act on the part of any of the parties hereto, anything herein to the contrary
notwithstanding.


Section
8.10.        Appointment of Co-Trustee or Separate Trustee. Notwithstanding any other provisions hereof, at any time, for the purpose of meeting any legal requirements of any
jurisdiction in which any part of the assets of the Trust may at the time be located, the Master Servicer and the Trustee or the
Delaware Trustee, as applicable, acting jointly shall have the power and shall execute and deliver all instruments to appoint one
or more Persons approved by such trustee to act as co-trustee or co-trustees, jointly with such trustee, or separate trustee or
separate trustees, of all or any part of the assets of the Trust and to vest in such Person or Persons, in such capacity, such
title to the assets of the Trust, or any part thereof, and, subject to the other provisions of this Section 8.10, such powers,
duties, obligations, rights and trusts as the Master Servicer and the Trustee or the Delaware Trustee, as applicable, may consider
necessary or desirable; provided, that the Trustee or the Delaware Trustee, as applicable, shall remain liable for all of its
obligations and duties under this Agreement. If the Master Servicer shall not have joined in such appointment within 15 days after
the receipt by it of a request so to do, or in case an Event of Default shall have occurred and be continuing, the Trustee or the
Delaware Trustee, as applicable, alone shall have the power to make such appointment; provided, that such trustee shall
remain liable for all of its obligations and duties under this Agreement. No co-trustee or separate trustee hereunder shall be
required to meet the terms of eligibility as a successor trustee under Section 8.06 hereunder and no notice to Certificateholders
of the appointment of co-trustee(s) or separate trustee(s) shall be required under Section 8.08 hereof.


In the case of any appointment of a co-trustee or separate trustee
pursuant to this Section 8.10, all rights, powers, duties and obligations conferred or imposed upon the Trustee or the Delaware
Trustee, as applicable, shall be conferred or imposed upon and exercised or performed by the Trustee or the Delaware Trustee, as
applicable, and such separate trustee or co-trustee jointly and severally, except to the extent that under any law of any
jurisdiction in which any particular act or acts are to be performed by the Trustee or the Delaware Trustee, as applicable (whether
as Trustee or Delaware Trustee hereunder or as successor to the Master Servicer hereunder), such trustee shall be incompetent or
unqualified to perform such act or acts, in which event such rights, powers, duties and obligations (including the holding of title
to the assets of the Trust or any portion thereof in any such jurisdiction) shall be exercised and performed by such separate
trustee or co-trustee at the direction of the Trustee or the Delaware Trustee, as applicable.


Any notice, request or other writing given to the Trustee or the
Delaware Trustee shall be deemed to have been given to each of the then related separate trustee(s) and co-trustee(s), as
effectively as if given to each of them. Every instrument appointing any separate trustee(s) or co-trustee(s) shall refer to this
Agreement and the conditions of this Article VIII. Each separate trustee and co-trustee, upon its acceptance of the trusts
conferred, shall be vested with the estates or property specified in its instrument of appointment, either jointly with the Trustee
or the Delaware Trustee, as applicable, or separately, as may be provided therein, subject to all the provisions of this Agreement,
specifically including every provision of this Agreement relating to the conduct of, affecting the liability of, or affording
protection to, the Trustee or the Delaware Trustee, as applicable. Every such instrument shall be filed with the Trustee or the
Delaware Trustee, as applicable.


Any separate trustee or co-trustee may, at any time, constitute the
Trustee or the Delaware Trustee, as applicable, its agent or attorney-in-fact, with full power and authority, to the extent not
prohibited by law, to do any lawful act under or in respect of this Agreement on its behalf and in its name. If any separate
trustee or co-trustee shall die, become incapable of acting, resign or be removed, all of its estates, properties, rights, remedies
and the trust shall vest in and be exercised by the Trustee or the Delaware Trustee, as applicable, to the extent permitted by law,
without the appointment of a new or successor trustee.


Section
8.11.        Authenticating Agents. The Trustee may
appoint one or more Authenticating Agents which shall be authorized to act on behalf of the Trustee in authenticating Certificates.
Wherever reference is made in this Agreement to the authentication of Certificates by the Trustee or the Trustee’s
certificate of authentication, such reference shall be deemed to include authentication on behalf of the Trustee by an
Authenticating Agent and a certificate of authentication executed on behalf of the Trustee by an Authenticating Agent. Each
Authenticating Agent must be acceptable to the Master Servicer and must be a corporation, trust company or banking association
organized and doing business under the laws of the United States of America or of any state, having a principal office and place of
business in New York, New York, having a combined capital and surplus of at least $15,000,000, authorized under such laws to do a
trust business and subject to supervision or examination by federal or state authorities.


Any corporation into which any Authenticating Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting from any merger, conversion or consolidation to which
any Authenticating Agent shall be a party, or any corporation succeeding to the corporate agency business of any Authenticating
Agent, shall continue to be the Authenticating Agent so long as it shall be eligible in accordance with the provisions of the first
paragraph of this Section 8.11 without the execution or filing of any paper or any further act on the part of the Trustee or the
Authenticating Agent.


Any Authenticating Agent may at any time resign by giving written
notice of resignation to the Trustee and the Master Servicer. The Trustee may, upon prior written approval of the Master Servicer,
at any time terminate the agency of any Authenticating Agent by giving written notice of termination to such Authenticating Agent
and to the Master Servicer. Upon receiving a notice of resignation or upon such a termination, or in case at any time any
Authenticating Agent shall cease to be eligible in accordance with the provisions of the first paragraph of this Section 8.11, the
Trustee may appoint, upon prior written approval of the Master Servicer, a successor Authenticating Agent, shall give written
notice of such appointment to the Master Servicer and shall mail notice of such appointment to all Certificateholders. Any
successor Authenticating Agent upon acceptance of its appointment hereunder shall become vested with all the rights, powers, duties
and responsibilities of its predecessor hereunder, with like effect as if originally named as Authenticating Agent. Any reasonable
compensation paid to an Authenticating Agent shall be a reimbursable expense pursuant to Section 8.05 if paid by the
Trustee.


Section
8.12.        Paying Agents. The Trustee may appoint one
or more Paying Agents which shall be authorized to act on behalf of the Trustee in making withdrawals from the Certificate Account,
and distributions to Certificateholders as provided in Section 4.01, Section 4.04(a) and Section 9.01(b) to the extent directed to
do so by the Master Servicer. Wherever reference is made in this Agreement to the withdrawal from the Certificate Account by the
Trustee, such reference shall be deemed to include such a withdrawal on behalf of the Trustee by a Paying Agent. Whenever reference
is made in this Agreement to a distribution by the Trustee or the furnishing of a statement to Certificateholders by the Trustee,
such reference shall be deemed to include such a distribution or furnishing on behalf of the Trustee by a Paying Agent. Each Paying
Agent shall provide to the Trustee such information concerning the Certificate Account as the Trustee shall request from time to
time. Each Paying Agent must be reasonably acceptable to the Master Servicer and must be a corporation, trust company or banking
association organized and doing business under the laws of the United States of America or of any state, having a principal office
and place of business in New York, New York, having a combined capital and surplus of at least $15,000,000, authorized under such
laws to do a trust business and subject to supervision or examination by federal or state authorities.


Any corporation into which any Paying Agent may be merged or converted
or with which it may be consolidated, or any corporation resulting from any merger, conversion or consolidation to which any Paying
Agent shall be a party, or any corporation succeeding to the corporate agency business of any Paying Agent, shall continue to be
the Paying Agent provided that such corporation after the consummation of such merger, conversion, consolidation or succession
meets the eligibility requirements of this Section 8.12.


Any Paying Agent may at any time resign by giving written notice of
resignation to the Trustee and to the Master Servicer; provided, that the Paying Agent has returned to the Certificate Account or
otherwise accounted, to the reasonable satisfaction of the Master Servicer, for all amounts it has withdrawn from the Certificate
Account. The Trustee may, upon prior written approval of the Master Servicer, at any time terminate the agency of any Paying Agent
by giving written notice of termination to such Paying Agent and to the Master Servicer. Upon receiving a notice of resignation or
upon such a termination, or in case at any time any Paying Agent shall cease to be eligible in accordance with the provisions of
the first paragraph of this Section 8.12, the Trustee may appoint, upon prior written approval of the Master Servicer, a successor
Paying Agent, shall give written notice of such appointment to the Master Servicer and shall mail notice of such appointment to all
Certificateholders. Any successor Paying Agent upon acceptance of its appointment hereunder shall become vested with all the
rights, powers, duties and responsibilities of its predecessor hereunder, with like effect as if originally named as Paying Agent.
Any reasonable compensation paid to any Paying Agent shall be a reimbursable expense pursuant to Section 8.05 if paid by the
Trustee.


Section
8.13.        Duties of Delaware Trustee.


(a)        The Delaware Trustee is
appointed to serve as the trustee of the Trust in the State of Delaware for the sole purpose of satisfying the requirement of
Section 3807(a) of the Statutory Trust Statute that the Trust have at least one trustee with a principal place of business in
Delaware.  It is understood and agreed by the parties hereto that the Delaware Trustee shall have none of the duties or
liabilities of the Trustee.


(b)        The duties of the
Delaware Trustee shall be limited to (i) accepting legal process served on the Trust in the State of Delaware, (ii) the execution
of any certificates with respect to the Trust required to be filed with the Secretary of State which the Delaware Trustee is
required to execute under Section 3811 of the Statutory Trust Statute and (iii) such other duties as are set forth in this Article
VIII.  To the extent that, at law or in equity, the Delaware Trustee has duties (including fiduciary duties) and liabilities
relating thereto to the Trust or the Holders of the REMIC I Regular Interests or the Certificates, it is hereby understood and
agreed by the parties hereto that such duties and liabilities are replaced by the duties and liabilities of the Delaware Trustee
expressly set forth in this Agreement.


Section
8.14.        Amendment to Certificate of Trust. 
If at any time required by Section 3810 of the Statutory Trust Statute, the Trustee, the Delaware Trustee and any other trustee of
the Trust shall cause an amendment to the Certificate of Trust to be filed with the Secretary of State in accordance with the
provisions of such Section 3810.


Section
8.15.        Yield Maintenance Agreement and Novation Agreement.  The Trust shall have the power and authority, and the Trustee is hereby authorized and directed, to (i) enter into
and perform the obligations of the Trust under the Yield Maintenance Agreement and the Novation Agreement and (ii) exercise and
enforce the rights of the Trust as specified therein.


ARTICLE IX



Termination 


Section
9.01.        Termination Upon Purchase by the Master Servicer or Liquidation of All Mortgage
Loans.


(a)        Except as otherwise set
forth in this Article IX, including, without limitation, the obligation of the Master Servicer to make payments to
Certificateholders as hereafter set forth, the Trust and the respective obligations and responsibilities of the Company, the Master
Servicer, the Trustee and the Delaware Trustee created hereby shall terminate in accordance with Section 3808 of the Statutory
Trust Statute upon (i) the purchase by the Master Servicer pursuant to the following paragraph of this Section 9.01(a) of all
Mortgage Loans (other than Liquidated Mortgage Loans), all property acquired in respect of any Mortgage Loan remaining in the Trust
and all other property included in any REMIC formed under this Agreement at a price equal to the sum of (x) the excess of (A) 100%
of the aggregate outstanding Principal Balance of such Mortgage Loans (other than Liquidated Mortgage Loans) plus accrued interest
at the applicable Pass-Through Rate with respect to such Mortgage Loan (other than a Liquidated Mortgage Loan) through the last day
of the month of such purchase, over (B) with respect to any Mortgage Loan which is not a Liquidated Mortgage Loan, the amount of
the Bankruptcy Loss incurred with respect to such Mortgage Loan as of the date of such purchase by the Master Servicer to the
extent that the Principal Balance of such Mortgage Loan has not been previously reduced by such Bankruptcy Loss, and (y) without
duplication, the appraised fair market value as of the effective date of the termination of the Trust of (A) all property in the
Trust which secured a Mortgage Loan and which was acquired by foreclosure or deed in lieu of foreclosure after the Cut-Off Date,
including related Insurance Proceeds, and (B) all other property included in any REMIC formed under this Agreement, any such
appraisal to be conducted by an appraiser mutually agreed upon by the Master Servicer and the Trustee, less the sum of all
unreimbursed advances made by the Master Servicer pursuant to this Agreement or by a Servicer pursuant to its Selling and Servicing
Contract, other than advances made with respect to Mortgage Loans as to which the Master Servicer expects at the time of such
purchase, in its sole judgment, that foreclosure is not imminent, or (ii) the later of the final payment or other liquidation (or
any advance with respect thereto) of the last Mortgage Loan remaining in the Trust or the disposition of all property acquired upon
foreclosure in respect of any Mortgage Loan, and the payment to the Certificateholders of all amounts required to be paid to them
hereunder; provided, however, that in no event shall the Trust continue beyond the expiration of 21 years from the death of the
survivor of the issue of Joseph P. Kennedy, the late ambassador of the United States to the Court of St. James, living on the date
hereof. Neither the Master Servicer nor any Servicer shall have any further right to reimbursement by the Trust for any advance
that is used to reduce the purchase price of the Mortgage Loans pursuant to the immediately preceding sentence.



            On any Distribution Date after the
Clean-Up Call Option Date, the Master Servicer may purchase the outstanding Mortgage Loans (other than Liquidated Mortgage Loans),
all property acquired in respect of any Mortgage Loan remaining in the Trust and all other property included in any REMIC formed
under this Agreement at the price stated in clause (i) of the preceding paragraph; provided, that the Master Servicer may not so purchase the outstanding Mortgage Loans (other than Liquidated
Mortgage Loans), all property acquired in respect of any Mortgage Loan remaining in the Trust and all other property included in
any REMIC formed under this Agreement if the price stated in clause (i) of the preceding paragraph exceeds the fair market value,
determined in accordance with prudent industry practices, of all outstanding Mortgage Loans (other than Liquidated Mortgage Loans),
all property acquired in respect of any Mortgage Loan remaining in the Trust and all other property included in any REMIC formed
under this Agreement.  If such right is exercised, the Master Servicer shall
provide to the Trustee (and to the Company, if the Company is no longer acting as Master Servicer) the written certification of an
officer of the Master Servicer (which certification shall include a statement to the effect that all amounts required to be paid in
order to purchase the Mortgage Loans have been deposited in the Certificate Account) and the Trustee on behalf of the Trust shall
promptly execute all instruments as may be necessary to release and assign to the Master Servicer the Mortgage Loans (other than Liquidated Mortgage Loans), all property acquired in respect of
any Mortgage Loan remaining in the Trust and all other property included in any REMIC formed under this
Agreement.


In no event shall the Master Servicer be required to expend any
amounts other than those described in the first paragraph of this Section 9.01(a) in order to terminate the Trust or purchase the
Mortgage Loans under this Section 9.01, and in no event shall the Company be required to expend any amounts in connection with such
termination or purchase.


(b)        In the event that the
Master Servicer elects to exercise its purchase option as provided in Section 9.01(a), the Master Servicer shall provide to the
Trustee and the Delaware Trustee (and to the Company, if the Company is no longer acting as Master Servicer) notice thereof not
less than 40 days prior to the date of the final distribution to Certificateholders.  Notice of such purchase, specifying the
date upon which the Certificateholders may surrender their Certificates to the Trustee for payment and cancellation, shall be given
promptly by letter from the Trustee to Certificateholders mailed not less than 30 days prior to such final distribution, specifying
(i) the date upon which final payment of the Certificates will be made upon presentation and surrender of Certificates at the
office of the Certificate Registrar therein designated (the “Termination Date”), (ii) the amount of such final
payment (the “Termination Payment”) and (iii) that the Record Date otherwise applicable to the Distribution Date
upon which the Termination Date occurs is not applicable, payments being made only upon presentation and surrender of the
Certificates at the office of the Certificate Registrar therein specified. Upon any such notice, the Certificate Account shall
terminate subject to the Master Servicer’s obligation to hold all amounts payable to Certificateholders in trust without
interest pending such payment.


In the event that all of the Certificateholders shall not surrender
their Certificates for cancellation within six months after the Termination Date, the Master Servicer shall give a second written
notice to the remaining Certificateholders to surrender their Certificates for cancellation and receive the Termination Payment
with respect thereto. If within one year after the second notice all the Certificates shall not have been surrendered for
cancellation, the Master Servicer may take appropriate steps to contact the remaining Certificateholders concerning surrender of
their Certificates, and the cost thereof shall be paid out of the funds and other assets which remain in trust
hereunder.


Upon the completion of winding up of the Trust, including the payment
or the making reasonable provision for payment of all obligations of the Trust in accordance with Section 3808(e) of the Statutory
Trust Statute, the Trustee, the Delaware Trustee and any other trustee hereunder shall file a certificate of cancellation with the
Secretary of State in accordance with Section 3810 of the Statutory Trust Statute, at which time the Trust and this Agreement shall
terminate.  The Master Servicer shall act as the liquidator of the Trust and shall be responsible for taking all actions in
connection with winding up the Trust, in accordance with the requirements of this Agreement (including Section 9.02) and applicable
law.


Section
9.02.        Additional Termination Requirements.


(a)        In the event the Master
Servicer exercises its purchase option as provided in Section 9.01, REMIC I and REMIC II shall be terminated in accordance with the
following additional requirements, unless the Master Servicer, at its own expense, obtains for the Trustee an Opinion of Counsel to
the effect that the failure of REMIC I and REMIC II to comply with the requirements of this Section 9.02 will not (i) result in the
imposition of taxes on “prohibited transactions” of REMIC I and REMIC II as described in Section 860F of the Code, or
(ii) cause REMIC I or REMIC II to fail to qualify as a REMIC at any time that any Certificates are outstanding:


(i)                 
Within 90 days prior to the final Distribution Date set forth in the notice given by the Trustee under Section 9.01, the Tax
Matters Person shall prepare the documentation required and the Tax Matters Person and the Trustee shall adopt a plan of complete
liquidation on behalf of REMIC I and REMIC II meeting the requirements of a qualified liquidation under Section 860F of the Code
and any regulations thereunder, as evidenced by an Opinion of Counsel obtained at the expense of the Master Servicer, on behalf of
REMIC I and REMIC II; and


(ii)                At or after the
time of adoption of such a plan of complete liquidation and at or prior to the final Distribution Date, the Master Servicer on
behalf of the Trust shall sell all of the assets of REMIC I and REMIC II to the Master Servicer for cash in the amount specified in
Section 9.01.


(b)        By its acceptance of any
Residual Certificate, the Holder thereof hereby agrees to authorize the Tax Matters Person and the Trustee to adopt such a plan of
complete liquidation and to take such other action in connection therewith as may be reasonably necessary.


Section
9.03.        Trust Irrevocable. Except as expressly
provided herein, the trust created hereby is irrevocable.


ARTICLE X



Miscellaneous Provisions 


Section
10.01.    Amendment.


(a)        This Agreement may be
amended from time to time by the Master Servicer, the Company and the Trustee, without the consent of any of the
Certificateholders:


(i)         to cure any ambiguity;


(ii)        to correct or supplement any provision herein which may be defective or
inconsistent with any other provisions herein;


(iii)       to comply with any requirements imposed by the Code or any regulations
thereunder;


(iv)       to correct the description of any property at any time included in REMIC I or REMIC
II, or to assure the conveyance to the Trust of any property included in REMIC I or REMIC II;


(v)        pursuant to Section 5.01(c)(v); and


(vi)       to add any provision to, or amend any provision in, this Agreement, provided that
such amendment or addition does not adversely affect in any material respect the interests of any Certificateholder;


provided, however, that any such amendment which modifies the rights or obligations of the Delaware Trustee hereunder shall
require the consent of the Delaware Trustee. No such amendment (other than one entered into pursuant to clause (iii) of the
preceding sentence) shall change the powers of the Master Servicer. Prior to entering into any amendment (other than one entered
into pursuant to clause (iii) of the second preceding sentence) without the consent of Certificateholders pursuant to this
paragraph, the Trustee shall require an Opinion of Counsel addressed to the Trust and the Trustee to the effect that such amendment
is permitted under this Agreement and has no material adverse effect on the interests of the Certificateholders; provided,
however, that no such Opinion of Counsel shall be required if the Company obtains a letter from each Rating Agency stating
that the amendment would not result in the downgrading or withdrawal of the respective ratings then assigned to the
Certificates.  Prior to entering into any amendment pursuant to clause (iii) of the third preceding sentence without the
consent of Certificateholders pursuant to this paragraph, the Trustee shall require an Opinion of Counsel to the effect that such
action is necessary or helpful to comply with the requirements imposed by the Code or any regulations thereunder and shall not
cause any REMIC formed under this Agreement to fail to qualify as such under the Code.


(b)        This Agreement may also
be amended from time to time by the Master Servicer, the Company and the Trustee with the consent of the Holders of Certificates
evidencing Percentage Interests aggregating not less than 66% of REMIC II for the purpose of adding any provisions to, or changing
in any manner or eliminating any of the provisions of, this Agreement or of modifying in any manner the rights of the
Certificateholders; provided, however, that no such amendment shall, without the consent of the Holder of each Certificate
affected thereby (i) reduce in any manner the amount of, or delay the timing of, distributions of principal or interest required to
be made hereunder or reduce the Certificateholder’s Percentage Interest, the Certificate Interest Rate or the Termination
Payment with respect to any of the Certificates, (ii) reduce the percentage of Percentage Interests specified in this Section 10.01
which are required to amend this Agreement, (iii) create or permit the creation of any lien against any part of REMIC I or REMIC
II, or (iv) modify any provision in any way which would permit an earlier retirement of the Certificates; provided, further,
that any such amendment which modifies the rights or obligations of the Delaware Trustee hereunder shall require the consent of the
Delaware Trustee.


Promptly after the execution of any such amendment, the Trustee shall
furnish written notification of the substance of such amendment to the Delaware Trustee and each Certificateholder. Any failure to
provide such notice, or any defect therein, shall not, however, in any way impair or affect the validity of any such
amendment.


It shall not be necessary for the consent of Certificateholders under
this Section 10.01 to approve the particular form of any proposed amendment, but it shall be sufficient if such consent shall
approve the substance thereof. The manner of obtaining such consents and of evidencing the authorization of the execution thereof
by Certificateholders shall be subject to such reasonable regulations as the Trustee may prescribe.


Section
10.02.    Recordation of Agreement. To the extent permitted by applicable
law, this Agreement is subject to recordation in all appropriate public offices for real property records in all the counties or
the comparable jurisdictions in which any Mortgaged Property is situated, and in any other appropriate public recording office or
elsewhere, such recordation to be effected by the Company and at its expense only if such recordation is reasonably necessary or
required to effectuate the duties and powers of the Master Servicer provided to it under this Agreement.


Section
10.03.    Limitation on Rights of Certificateholders. The death or
incapacity of any Certificateholder shall not operate to terminate this Agreement or the Trust, nor entitle such
Certificateholder’s legal representatives or heirs to claim an accounting or to take any action or proceeding in any court
for a partition or winding-up of the Trust, nor otherwise affect the rights, obligations and liabilities of the parties hereto or
any of them.


No Certificateholder shall have any right to vote or in any manner
otherwise to control the operation and management of the Trust or the obligations of the parties hereto (except as provided in
Section 5.09, Section 7.01, Section 8.01, Section 8.02, Section 8.07, Section 10.01 and this Section 10.03), nor shall anything
herein set forth, or contained in the terms of the Certificates, be construed so as to constitute the Certificateholders from time
to time as partners or members of an association; nor shall any Certificateholder be under any liability to any third person by
reason of any action taken by the parties to this Agreement pursuant to any provision hereof.


No Certificateholder shall have any right by virtue or by availing of
any provision of this Agreement to institute any suit, action or proceeding in equity or at law upon or under or with respect to
this Agreement, unless such Holder previously shall have given to the Trustee a written notice of default and of the continuance
thereof, as hereinbefore provided, and unless also the Holders of Certificates evidencing Percentage Interests aggregating not less
than 25% of REMIC II shall have made written request upon the Trustee to institute such action, suit or proceeding in its own name
as Trustee hereunder and shall have offered to the Trustee such reasonable indemnity as it may require against the costs, expenses
and liabilities to be incurred therein or thereby, and the Trustee, for 60 days after its receipt of such notice, request and offer
of indemnity, shall have neglected or refused to institute any such action, suit or proceeding. However, the Trustee is under no
obligation to exercise any of the extraordinary trusts or powers vested in it by this Agreement or to make any investigation of
matters arising hereunder or to institute, conduct or defend any litigation hereunder or in relation hereto at the request, order
or direction of any of the Certificateholders unless such Certificateholders have offered to the Trustee reasonable security or
indemnity against the costs, expenses and liabilities which may be incurred therein or thereby. It is understood and intended, and
expressly covenanted by each Certificateholder with every other Certificateholder and the Trustee, that no one or more Holders of
Certificates shall have any right in any manner whatever by virtue or by availing of any provision of this Agreement to affect,
disturb or prejudice the rights of the Holders of any other of such Certificates, or to obtain or seek to obtain priority over or
preference to any other such Holder, or to enforce any right under this Agreement, except in the manner herein provided and for the
equal, ratable and common benefit of all Certificateholders. For the protection and enforcement of the provisions of this Section
10.03, each and every Certificateholder and the Trustee shall be entitled to such relief as can be given either at law or in
equity.


Section
10.04.    Access to List of Certificateholders. The Certificate Registrar
shall furnish or cause to be furnished to the Trustee, within 30 days after receipt of a request by the Trustee in writing, a list,
in such form as the Trustee may reasonably require, of the names and addresses of the Certificateholders as of the most recent
Record Date for payment of distributions to such Certificateholders.


If three or more Certificateholders (hereinafter referred to as
“applicants”) apply in writing to the Trustee, and such application states that the applicants desire to
communicate with other Certificateholders with respect to their rights under this Agreement or under the Certificates and is
accompanied by a copy of the communication which such applicants propose to transmit, then the Trustee shall, within five Business
Days after the receipt of such list from the Certificate Registrar, afford such applicants access during normal business hours to
the most recent list of Certificateholders held by the Trustee. If such a list is as of a date more than 90 days prior to the date
of receipt of such applicants’ request, the Trustee shall promptly request from the Certificate Registrar a current list as
provided above, and shall afford such applicants access to such list promptly upon receipt.


Every Certificateholder, by receiving and holding the same, agrees
with the Master Servicer, the Trust, the Trustee and the Delaware Trustee that none of the Master Servicer, the Trust, the Trustee
or the Delaware Trustee shall be held accountable by reason of the disclosure of any such information as to the names and addresses
of the Certificateholders hereunder, regardless of the source from which such information was derived.


Section
10.05.    Governing Law. This Agreement shall be construed in accordance
with the laws of the State of Delaware without giving effect to its conflict of law provisions and the obligations, rights and
remedies of the parties hereunder shall be determined in accordance with such laws without giving effect to conflict of laws
provisions.


Section
10.06.    Notices. All demands, notices and communications hereunder shall
be in writing and shall be deemed to have been duly given if personally delivered at or mailed by registered or certified mail to
the applicable Notice Address. Notices to the Rating Agencies shall also be deemed to have been duly given if mailed by first class
mail, postage prepaid, to the above listed addresses of the Rating Agencies. Any notice required or permitted to be mailed to a
Certificateholder shall be given by first class mail, postage prepaid, at the address of such Holder as shown in the Certificate
Register. Any notice so mailed within the time prescribed in this Agreement shall be conclusively presumed to have been duly given,
whether or not the Certificateholder receives such notice.


Section
10.07.    Severability of Provisions. If any one or more of the covenants,
agreements, provisions or terms of this Agreement shall be for any reason whatsoever held invalid, then such covenants, agreements,
provisions or terms shall be deemed severable from the remaining covenants, agreements, provisions or terms of this Agreement and
shall in no way affect the validity or enforceability of the other provisions of this Agreement or of the Certificates or the
rights of the Holders thereof.


Section
10.08.    Counterpart Signatures. For the purpose of facilitating the
recordation of this Agreement as herein provided and for other purposes, this Agreement may be executed simultaneously in any
number of counterparts, each of which counterparts shall be deemed to be an original, and such counterparts shall constitute but
one and the same instrument.


Section
10.09.    Benefits of Agreement. Nothing in this Agreement or in any
Certificate, expressed or implied, shall give to any Person, other than the parties hereto and their respective successors
hereunder, any separate trustee or co-trustee appointed under Section 8.10 and the Certificateholders, any benefit or any legal or
equitable right, remedy or claim under this Agreement.


Section
10.10.    Notices and Copies to Rating Agencies.


(a)        The Trustee shall notify
the Rating Agencies of the occurrence of any of the following events, in the manner provided in Section 10.06:


(i)         the occurrence of an Event of Default pursuant to Section 7.01, subject
to the provisions of Section 8.01(d); and


(ii)        the appointment of a successor Master Servicer pursuant to Section
7.02;


(b)        The Master Servicer
shall notify the Rating Agencies of the occurrence of any of the following events, or in the case of clauses (iii), (iv), (vii) and
(viii) promptly upon receiving notice thereof, in the manner provided in Section 10.06:


(i)        
any amendment of this Agreement pursuant to Section 10.01;


(ii)        the appointment of a successor Trustee or successor Delaware Trustee pursuant
to Section 8.08;


(iii)       the filing of any claim under or the cancellation or modification of any fidelity
bond and errors and omissions coverage pursuant to Section 3.01 and Section 3.06 with respect to the Master Servicer or any
Servicer;


(iv)       any change in the location of the Certificate Account, any Custodial Account for
P&I or any Custodial Account for Reserves;


(v)        the purchase of any Mortgage Loan pursuant to a Purchase Obligation or as
permitted by this Agreement or the purchase of the outstanding Mortgage Loans pursuant to Section 9.01;


(vi)       the occurrence of the final Distribution Date or the termination of the trust
pursuant to Section 9.01(a)(ii);


(vii)      the failure of the Master Servicer to make a Monthly P&I Advance following a
determination on the Determination Date that the Master Servicer would make such advance pursuant to Section 4.02;
and


(viii)      the failure of the Master Servicer to make a determination on the Determination Date
regarding whether it would make a Monthly P&I Advance when a shortfall exists between (x) payments scheduled to be received in
respect of the Mortgage Loans and (y) the amounts actually deposited in the Certificate Account on account of such payments,
pursuant to Section 4.02.


The Master Servicer shall provide copies of the statements
pursuant to Section 4.02, Section 4.05, Section 3.12, Section 3.13 or Section 3.15 or any other statements or reports to the Rating
Agencies in such time and manner that such statements or determinations are required to be provided to Certificateholders. With
respect to the reports described in the second paragraph of Section 4.05, the Master Servicer shall provide such reports to the
Rating Agencies in respect of each Distribution Date, without regard to whether any Certificateholder or the Trustee or the
Delaware Trustee has requested such report for such Distribution Date.




 





IN WITNESS WHEREOF, the Company, the Trustee and the Delaware Trustee
have caused their names to be signed hereto by their respective officers, thereunto duly authorized, all as of the day and year
first above written.


WASHINGTON MUTUAL MORTGAGE SECURITIES
CORP.







By:    /s/ Barbara Loper

Name: Barbara Loper

Title: Vice President


DEUTSCHE BANK NATIONAL TRUST COMPANY,

as Trustee







By:    /s/ Barbara Campbell

Name: Barbara Campbell

Title: Assistant Vice President


By:    /s/ Ronaldo Reyes

Name:  Ronaldo Reyes

Title: Assistant Vice President


DEUTSCHE BANK TRUST COMPANY DELAWARE,

as Delaware Trustee







By:    /s/ Elizabeth B. Ferry

Name:  Elizabeth B. Ferry

Title:  Assistant Vice President


[Signature
page to Pooling and Servicing Agreement for WaMu Series 2005-AR1]










Appendix
1:  Definition of Class LT Principal Reduction Amounts


 


	 	          Copies of
Appendix 1 (which has been intentionally omitted from this filing) may be obtained from Washington Mutual Mortgage Securities Corp.
or Deutsche Bank National Trust Company by contacting:



 


	 	      in the case of Washington
Mutual Mortgage Securities Corp., 



 


	 	        Laura Kelsey

         Master Servicing Department

         Washington Mutual Mortgage Securities Corp.

         75 N. Fairway Drive,VHF2A01

         Vernon Hills, IL 60061

         Telephone:  (847) 393-5198

         Facsimile:     (847) 549-2997 



 


	 	      in the case of Deutsche Bank
National Trust Company, 



 


	 	        Alan Sueda

         Trust Administrator

         Deutsche Bank National Trust Company

         1761 E. St. Andrew Place

         Santa Ana, CA 92705

         Telephone:  (714) 247-6315

         Facsimile:    (714) 247-6329



 







Exhibit A

CUSIP 939336 X4 0


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-1A


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class A-1A Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$400,000,000.00


Class A-1A Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-1A
Principal Balance

as of the Cut-Off Date: $716,000,000.00


Cede & Co.


Registered Owner


Certificate No. 1




 


Exhibit A

CUSIP 939336 X4 0


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-1A


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class A-1A Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$316,000,000.00


Class A-1A Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-1A
Principal Balance

as of the Cut-Off Date: $716,000,000.00


Cede & Co.


Registered Owner


Certificate No. 2









Exhibit A

CUSIP 939336 X5 7


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-1B


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


The Class A-1B Certificates will provide credit support to another Class
of Certificates, as described in the Pooling Agreement.


Series
2005-AR1                                                                                    
Portion of the Class A-1B Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$400,000,000.00


Class A-1B Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-1B
Principal Balance

as of the Cut-Off Date: $477,350,000.00


Cede & Co.


Registered Owner


Certificate No. 1









Exhibit A

CUSIP 939336 X5 7


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-1B


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


The Class A-1B Certificates will provide credit support to another Class
of Certificates, as described in the Pooling Agreement.


Series
2005-AR1                                                                                    
Portion of the Class A-1B Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$77,350,000.00


Class A-1B Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-1B
Principal Balance

as of the Cut-Off Date: $477,350,000.00


Cede & Co.


Registered Owner


Certificate No. 2


 









Exhibit A

CUSIP 939336 X6 5


 


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-2A1


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class A-2A1 Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$400,000,000.00


Class A-2A1 Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-2A1
Principal Balance

as of the Cut-Off Date: $764,000,000.00


Cede & Co.


Registered Owner


Certificate No. 1









Exhibit A

CUSIP 939336 X6 5


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-2A1


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class A-2A1 Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$364,000,000.00


Class A-2A1 Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-2A1
Principal Balance

as of the Cut-Off Date: $764,000,000.00


Cede & Co.


Registered Owner


Certificate No. 2


 


 









Exhibit A

CUSIP 939336 X7 3


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-2A2


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class A-2A2 Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$352,300,000.00


Class A-2A2 Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-2A2
Principal Balance

as of the Cut-Off Date: $352,300,000.00


Cede & Co.


Registered Owner


 









Exhibit A

CUSIP 939336 X8 1


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-2A3


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class A-2A3 Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$158,479,000.00


Class A-2A3 Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-2A3
Principal Balance

as of the Cut-Off Date: $158,479,000.00


Cede & Co.


Registered Owner


 









Exhibit A

CUSIP 939336 X9 9


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-2B


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain rights specified in the Pooling Agreement. The issue date of this Certificate is January
18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


The Class A-2B Certificates will provide credit support to another Class
of Certificates, as described in the Pooling Agreement.


Series
2005-AR1                                                                                    
Portion of the Class A-2B Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$225,000,000.00


Class A-2B Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-2B
Principal Balance

as of the Cut-Off Date: $225,000,000.00


Cede & Co.


Registered Owner


 









Exhibit A

CUSIP 939336 Z2 2


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class A-3


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended. The issue date of this Certificate is January 18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class A-3 Principal Balance as of


                                                                                                               
the Cut-Off Date Evidenced by this Certificate:


                                                                                                               
$100,000,000.00


Class A-3 Certificate Interest Rate:
Variable


Cut-Off Date:
January 1, 2005


First Distribution
Date: February 25, 2005


Last Scheduled
Distribution Date: January 25, 2045


Class A-3
Principal Balance

as of the Cut-Off Date: $100,000,000.00


Cede & Co.


Registered Owner


 









Exhibit A

CUSIP 939336 Y5 6


WaMu MORTGAGE PASS-THROUGH
CERTIFICATE


Class X


Evidencing a beneficial interest in a pool of assets consisting of
beneficial interests in another pool of assets consisting of, among other things, conventional one- to four-family mortgage loans
formed and administered by


WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended, together with certain obligations specified in the Pooling Agreement. The issue date of this Certificate is
January 18, 2005.


Unless this Certificate is presented by an authorized representative of
The Depository Trust Company, a New York corporation (“DTC”), to the Company or its agent for registration of transfer,
exchange, or payment, and any Certificate issued is registered in the name of Cede & Co. or such other name as is requested by
an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an
authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
inasmuch as the registered owner hereof, Cede & Co., has an interest herein.


Series
2005-AR1                                                                                    
Portion of the Class X Notional Amount as of the

Cut-Off Date Evidenced by this Certificate:

$2,971,414,173.00



Class X Certificate Interest Rate: Variable, applied to the Class X Notional
Amount



Cut-Off Date: January 1, 2005



First Distribution Date: February 25, 2005



Last Scheduled Distribution Date: January 25, 2045



Class X Principal Balance

as of the Cut-Off Date: $0.00


Class X Notional
Amount

as of the Cut-Off Date: $2,971,414,173.00


Cede & Co.


Registered Owner









Exhibit A

CUSIP 939336 Y2 3


WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


Class
B-1


Evidencing a beneficial interest in a pool of
assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to
four-family mortgage loans formed and administered by


WASHINGTON
MUTUAL MORTGAGE SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended (the “Code”). The issue date of this Certificate is January 18, 2005.


Unless this Certificate
is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the
Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of
Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co.
or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest
herein.


NO TRANSFER OF THIS CLASS B-1
CERTIFICATE WILL BE MADE UNLESS THE TRUSTEE HAS RECEIVED (I) AN OFFICER’S CERTIFICATE IN THE FORM DESCRIBED IN SECTION
5.01(g) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF COUNSEL ACCEPTABLE TO
AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND HOLDING OF THIS
CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED TRANSACTION UNDER
SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE, AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER
SERVICER OR THE COMPANY TO ANY OBLIGATION OR LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION
4975 OF THE CODE) IN ADDITION TO THOSE UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE
TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


NOTWITHSTANDING THE FOREGOING PARAGRAPH,
WITH RESPECT TO THE TRANSFER OF THIS CLASS B-1 CERTIFICATE TO DTC OR ANY OTHER CLEARING AGENCY OR ANY SUBSEQUENT TRANSFER OF ANY
INTEREST IN THIS CERTIFICATE FOR SO LONG AS THIS CERTIFICATE IS HELD BY DTC OR ANY OTHER CLEARING AGENCY, (I) AN OFFICER’S
CERTIFICATE (AND, IF APPLICABLE, A BENEFIT PLAN OPINION), AS DESCRIBED IN THE FOREGOING PARAGRAPH, SHALL NOT BE REQUIRED, AND (II)
THE FOLLOWING CONDITIONS SHALL APPLY:


1.             ANY TRANSFEREE OF THIS CERTIFICATE WILL BE DEEMED
TO HAVE REPRESENTED, BY VIRTUE OF ITS ACQUISITION OR HOLDING OF THIS CERTIFICATE (OR INTEREST HEREIN), THAT EITHER (A) SUCH
TRANSFEREE IS NOT AN EMPLOYEE BENEFIT OR OTHER PLAN SUBJECT TO THE PROHIBITED TRANSACTION PROVISIONS OF ERISA OR SECTION 4975 OF
THE CODE, OR ANY PERSON (INCLUDING AN INVESTMENT MANAGER, A NAMED FIDUCIARY OR A TRUSTEE OF ANY SUCH PLAN) ACTING, DIRECTLY OR
INDIRECTLY, ON BEHALF OF OR PURCHASING THIS CERTIFICATE WITH “PLAN ASSETS” OF ANY SUCH PLAN (A “PLAN
INVESTOR”), (B) SUCH TRANSFEREE IS AN INSURANCE COMPANY, THE SOURCE OF FUNDS TO BE USED BY IT TO ACQUIRE OR HOLD THIS
CERTIFICATE IS AN “INSURANCE COMPANY GENERAL ACCOUNT” (WITHIN THE MEANING OF DEPARTMENT OF LABOR PROHIBITED TRANSACTION
CLASS EXEMPTION (“PTCE”) 95-60), AND THE CONDITIONS IN SECTIONS I AND III OF PTCE 95-60 HAVE BEEN SATISFIED (EACH
ENTITY THAT SATISFIES THIS CLAUSE (B), A “COMPLYING INSURANCE COMPANY”) OR (C) THIS CERTIFICATE WAS RATED
“BBB-” OR BETTER (OR ITS EQUIVALENT) BY AT LEAST ONE OF THE RATING AGENCIES AT THE TIME OF SUCH TRANSFEREE’S
ACQUISITION OF THIS CERTIFICATE (OR INTEREST HEREIN); AND


2.             IF THIS CERTIFICATE (OR ANY INTEREST HEREIN) IS
ACQUIRED OR HELD IN VIOLATION OF THE PROVISIONS OF THE PRECEDING PARAGRAPH, THEN THE LAST PRECEDING TRANSFEREE THAT EITHER (I) IS
NOT A PLAN INVESTOR, (II) IS A COMPLYING INSURANCE COMPANY OR (III) ACQUIRED THIS CERTIFICATE AT A TIME WHEN THIS CERTIFICATE WAS
RATED “BBB-” OR BETTER (OR ITS EQUIVALENT) BY AT LEAST ONE OF THE RATING AGENCIES SHALL BE RESTORED, TO THE EXTENT
PERMITTED BY LAW, TO ALL RIGHTS AND OBLIGATIONS AS BENEFICIAL HOLDER THEREOF RETROACTIVE TO THE DATE OF TRANSFER OF THIS
CERTIFICATE BY SUCH PRECEDING TRANSFEREE.  NEITHER THE TRUST NOR THE TRUSTEE SHALL BE UNDER ANY LIABILITY TO ANY PERSON FOR
MAKING ANY PAYMENTS DUE ON THIS CERTIFICATE TO SUCH PRECEDING TRANSFEREE.


ANY PURPORTED BENEFICIAL HOLDER WHOSE
ACQUISITION OR HOLDING OF THIS CERTIFICATE (OR INTEREST HEREIN) WAS EFFECTED IN VIOLATION OF THE RESTRICTIONS IN SECTION 5.01(g) OF
THE POOLING AGREEMENT SHALL INDEMNIFY AND HOLD HARMLESS THE COMPANY, THE TRUSTEE, THE MASTER SERVICER, THE TRUST AND THE
UNDERWRITERS FROM AND AGAINST ANY AND ALL LIABILITIES, CLAIMS, COSTS OR EXPENSES INCURRED BY SUCH PARTIES AS A RESULT OF SUCH
ACQUISITION OR HOLDING.


The Class B-1 Certificates will be subordinate
in right of payment to and provide credit support to certain Classes of Certificates, as described in the Pooling
Agreement.


Series
2005-AR1                                                                                    
Portion of the Class B-1 Principal Balance as of the Cut-Off Date Evidenced by this Certificate:

$65,371,000.00


Class B-1 Certificate Interest Rate: Variable


Cut-Off Date: January 1, 2005


First Distribution Date: February 25,
2005


Last Scheduled Distribution Date: January 25,
2045


Class B-1
Principal Balance

as of the Cut-Off Date: $65,371,000.00


 


Cede & Co.


Registered Owner


 









Exhibit A

CUSIP 939336 Y3 1


 WaMu
MORTGAGE PASS-THROUGH CERTIFICATE


Class
B-2


Evidencing a beneficial interest in a pool of
assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to
four-family mortgage loans formed and administered by


WASHINGTON
MUTUAL MORTGAGE SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended (the “Code”). The issue date of this Certificate is January 18, 2005.


Unless this Certificate
is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the
Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of
Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co.
or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest
herein.


NO TRANSFER OF THIS CLASS B-2
CERTIFICATE WILL BE MADE UNLESS THE TRUSTEE HAS RECEIVED (I) AN OFFICER’S CERTIFICATE IN THE FORM DESCRIBED IN SECTION
5.01(g) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF COUNSEL ACCEPTABLE TO
AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND HOLDING OF THIS
CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED TRANSACTION UNDER
SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE, AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER
SERVICER OR THE COMPANY TO ANY OBLIGATION OR LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION
4975 OF THE CODE) IN ADDITION TO THOSE UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE
TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


NOTWITHSTANDING THE FOREGOING PARAGRAPH,
WITH RESPECT TO THE TRANSFER OF THIS CLASS B-2 CERTIFICATE TO DTC OR ANY OTHER CLEARING AGENCY OR ANY SUBSEQUENT TRANSFER OF ANY
INTEREST IN THIS CERTIFICATE FOR SO LONG AS THIS CERTIFICATE IS HELD BY DTC OR ANY OTHER CLEARING AGENCY, (I) AN OFFICER’S
CERTIFICATE (AND, IF APPLICABLE, A BENEFIT PLAN OPINION), AS DESCRIBED IN THE FOREGOING PARAGRAPH, SHALL NOT BE REQUIRED, AND (II)
THE FOLLOWING CONDITIONS SHALL APPLY:


1.             ANY TRANSFEREE OF THIS CERTIFICATE WILL BE DEEMED
TO HAVE REPRESENTED, BY VIRTUE OF ITS ACQUISITION OR HOLDING OF THIS CERTIFICATE (OR INTEREST HEREIN), THAT EITHER (A) SUCH
TRANSFEREE IS NOT AN EMPLOYEE BENEFIT OR OTHER PLAN SUBJECT TO THE PROHIBITED TRANSACTION PROVISIONS OF ERISA OR SECTION 4975 OF
THE CODE, OR ANY PERSON (INCLUDING AN INVESTMENT MANAGER, A NAMED FIDUCIARY OR A TRUSTEE OF ANY SUCH PLAN) ACTING, DIRECTLY OR
INDIRECTLY, ON BEHALF OF OR PURCHASING THIS CERTIFICATE WITH “PLAN ASSETS” OF ANY SUCH PLAN (A “PLAN
INVESTOR”), (B) SUCH TRANSFEREE IS AN INSURANCE COMPANY, THE SOURCE OF FUNDS TO BE USED BY IT TO ACQUIRE OR HOLD THIS
CERTIFICATE IS AN “INSURANCE COMPANY GENERAL ACCOUNT” (WITHIN THE MEANING OF DEPARTMENT OF LABOR PROHIBITED TRANSACTION
CLASS EXEMPTION (“PTCE”) 95-60), AND THE CONDITIONS IN SECTIONS I AND III OF PTCE 95-60 HAVE BEEN SATISFIED (EACH
ENTITY THAT SATISFIES THIS CLAUSE (B), A “COMPLYING INSURANCE COMPANY”) OR (C) THIS CERTIFICATE WAS RATED
“BBB-” OR BETTER (OR ITS EQUIVALENT) BY AT LEAST ONE OF THE RATING AGENCIES AT THE TIME OF SUCH TRANSFEREE’S
ACQUISITION OF THIS CERTIFICATE (OR INTEREST HEREIN); AND


2.             IF THIS CERTIFICATE (OR ANY INTEREST HEREIN) IS
ACQUIRED OR HELD IN VIOLATION OF THE PROVISIONS OF THE PRECEDING PARAGRAPH, THEN THE LAST PRECEDING TRANSFEREE THAT EITHER (I) IS
NOT A PLAN INVESTOR, (II) IS A COMPLYING INSURANCE COMPANY OR (III) ACQUIRED THIS CERTIFICATE AT A TIME WHEN THIS CERTIFICATE WAS
RATED “BBB-” OR BETTER (OR ITS EQUIVALENT) BY AT LEAST ONE OF THE RATING AGENCIES SHALL BE RESTORED, TO THE EXTENT
PERMITTED BY LAW, TO ALL RIGHTS AND OBLIGATIONS AS BENEFICIAL HOLDER THEREOF RETROACTIVE TO THE DATE OF TRANSFER OF THIS
CERTIFICATE BY SUCH PRECEDING TRANSFEREE.  NEITHER THE TRUST NOR THE TRUSTEE SHALL BE UNDER ANY LIABILITY TO ANY PERSON FOR
MAKING ANY PAYMENTS DUE ON THIS CERTIFICATE TO SUCH PRECEDING TRANSFEREE.


ANY PURPORTED BENEFICIAL HOLDER WHOSE
ACQUISITION OR HOLDING OF THIS CERTIFICATE (OR INTEREST HEREIN) WAS EFFECTED IN VIOLATION OF THE RESTRICTIONS IN SECTION 5.01(g) OF
THE POOLING AGREEMENT SHALL INDEMNIFY AND HOLD HARMLESS THE COMPANY, THE TRUSTEE, THE MASTER SERVICER, THE TRUST AND THE
UNDERWRITERS FROM AND AGAINST ANY AND ALL LIABILITIES, CLAIMS, COSTS OR EXPENSES INCURRED BY SUCH PARTIES AS A RESULT OF SUCH
ACQUISITION OR HOLDING.


The Class B-2 Certificates will be subordinate
in right of payment to and provide credit support to certain Classes of Certificates, as described in the Pooling
Agreement.


Series
2005-AR1                                                                                    
Portion of the Class B-2 Principal Balance as of the Cut-Off Date Evidenced by this Certificate:

$40,114,000.00


Class B-2 Certificate Interest Rate: Variable


Cut-Off Date: January 1, 2005


First Distribution Date: February 25,
2005


Last Scheduled Distribution Date: January 25,
2045


Class B-2
Principal Balance

as of the Cut-Off Date: $40,114,000.00


 


Cede & Co.


Registered Owner


 









Exhibit A

CUSIP 939336 Y4 9


 WaMu
MORTGAGE PASS-THROUGH CERTIFICATE


Class
B-3


Evidencing a beneficial interest in a pool of
assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to
four-family mortgage loans formed and administered by


WASHINGTON
MUTUAL MORTGAGE SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through Certificates
Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real estate mortgage
investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal Revenue Code of
1986, as amended (the “Code”). The issue date of this Certificate is January 18, 2005.


Unless this Certificate
is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the
Company or its agent for registration of transfer, exchange, or payment, and any Certificate issued is registered in the name of
Cede & Co. or such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co.
or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest
herein.


NO TRANSFER OF THIS CLASS B-3
CERTIFICATE WILL BE MADE UNLESS THE TRUSTEE HAS RECEIVED (I) AN OFFICER’S CERTIFICATE IN THE FORM DESCRIBED IN SECTION
5.01(g) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF COUNSEL ACCEPTABLE TO
AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND HOLDING OF THIS
CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED TRANSACTION UNDER
SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE, AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER
SERVICER OR THE COMPANY TO ANY OBLIGATION OR LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION
4975 OF THE CODE) IN ADDITION TO THOSE UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE
TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


NOTWITHSTANDING THE FOREGOING PARAGRAPH,
WITH RESPECT TO THE TRANSFER OF THIS CLASS B-3 CERTIFICATE TO DTC OR ANY OTHER CLEARING AGENCY OR ANY SUBSEQUENT TRANSFER OF ANY
INTEREST IN THIS CERTIFICATE FOR SO LONG AS THIS CERTIFICATE IS HELD BY DTC OR ANY OTHER CLEARING AGENCY, (I) AN OFFICER’S
CERTIFICATE (AND, IF APPLICABLE, A BENEFIT PLAN OPINION), AS DESCRIBED IN THE FOREGOING PARAGRAPH, SHALL NOT BE REQUIRED, AND (II)
THE FOLLOWING CONDITIONS SHALL APPLY:


1.             ANY TRANSFEREE OF THIS CERTIFICATE WILL BE DEEMED
TO HAVE REPRESENTED, BY VIRTUE OF ITS ACQUISITION OR HOLDING OF THIS CERTIFICATE (OR INTEREST HEREIN), THAT EITHER (A) SUCH
TRANSFEREE IS NOT AN EMPLOYEE BENEFIT OR OTHER PLAN SUBJECT TO THE PROHIBITED TRANSACTION PROVISIONS OF ERISA OR SECTION 4975 OF
THE CODE, OR ANY PERSON (INCLUDING AN INVESTMENT MANAGER, A NAMED FIDUCIARY OR A TRUSTEE OF ANY SUCH PLAN) ACTING, DIRECTLY OR
INDIRECTLY, ON BEHALF OF OR PURCHASING THIS CERTIFICATE WITH “PLAN ASSETS” OF ANY SUCH PLAN (A “PLAN
INVESTOR”), (B) SUCH TRANSFEREE IS AN INSURANCE COMPANY, THE SOURCE OF FUNDS TO BE USED BY IT TO ACQUIRE OR HOLD THIS
CERTIFICATE IS AN “INSURANCE COMPANY GENERAL ACCOUNT” (WITHIN THE MEANING OF DEPARTMENT OF LABOR PROHIBITED TRANSACTION
CLASS EXEMPTION (“PTCE”) 95-60), AND THE CONDITIONS IN SECTIONS I AND III OF PTCE 95-60 HAVE BEEN SATISFIED (EACH
ENTITY THAT SATISFIES THIS CLAUSE (B), A “COMPLYING INSURANCE COMPANY”) OR (C) THIS CERTIFICATE WAS RATED
“BBB-” OR BETTER (OR ITS EQUIVALENT) BY AT LEAST ONE OF THE RATING AGENCIES AT THE TIME OF SUCH TRANSFEREE’S
ACQUISITION OF THIS CERTIFICATE (OR INTEREST HEREIN); AND


2.             IF THIS CERTIFICATE (OR ANY INTEREST HEREIN) IS
ACQUIRED OR HELD IN VIOLATION OF THE PROVISIONS OF THE PRECEDING PARAGRAPH, THEN THE LAST PRECEDING TRANSFEREE THAT EITHER (I) IS
NOT A PLAN INVESTOR, (II) IS A COMPLYING INSURANCE COMPANY OR (III) ACQUIRED THIS CERTIFICATE AT A TIME WHEN THIS CERTIFICATE WAS
RATED “BBB-” OR BETTER (OR ITS EQUIVALENT) BY AT LEAST ONE OF THE RATING AGENCIES SHALL BE RESTORED, TO THE EXTENT
PERMITTED BY LAW, TO ALL RIGHTS AND OBLIGATIONS AS BENEFICIAL HOLDER THEREOF RETROACTIVE TO THE DATE OF TRANSFER OF THIS
CERTIFICATE BY SUCH PRECEDING TRANSFEREE.  NEITHER THE TRUST NOR THE TRUSTEE SHALL BE UNDER ANY LIABILITY TO ANY PERSON FOR
MAKING ANY PAYMENTS DUE ON THIS CERTIFICATE TO SUCH PRECEDING TRANSFEREE.


ANY PURPORTED BENEFICIAL HOLDER WHOSE
ACQUISITION OR HOLDING OF THIS CERTIFICATE (OR INTEREST HEREIN) WAS EFFECTED IN VIOLATION OF THE RESTRICTIONS IN SECTION 5.01(g) OF
THE POOLING AGREEMENT SHALL INDEMNIFY AND HOLD HARMLESS THE COMPANY, THE TRUSTEE, THE MASTER SERVICER, THE TRUST AND THE
UNDERWRITERS FROM AND AGAINST ANY AND ALL LIABILITIES, CLAIMS, COSTS OR EXPENSES INCURRED BY SUCH PARTIES AS A RESULT OF SUCH
ACQUISITION OR HOLDING.


The Class B-3 Certificates will be subordinate
in right of payment to and provide credit support to certain Classes of Certificates, as described in the Pooling
Agreement.


Series
2005-AR1                                                                                    
Portion of the Class B-3 Principal Balance as of the Cut-Off Date Evidenced by this Certificate:

$22,285,000.00


Class B-3 Certificate Interest Rate: Variable


Cut-Off Date: January 1, 2005


First Distribution Date: February 25,
2005


Last Scheduled Distribution Date: January 25,
2045


Class B-3
Principal Balance

as of the Cut-Off Date: $22,285,000.00


 


Cede & Co.


Registered Owner









Exhibit A






 WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


Class Y


Evidencing a beneficial interest in a pool of
assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to
four-family mortgage loans formed and administered by


WASHINGTON MUTUAL
MORTGAGE SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through
Certificates Series 2005-AR1 Trust. This Certificate represents certain rights specified in the Pooling Agreement. The issue date
of this Certificate is January 18, 2005.


IN THE CASE OF ANY CLASS Y CERTIFICATE
PRESENTED FOR REGISTRATION IN THE NAME OF ANY PERSON, THE TRUSTEE SHALL REQUIRE (I) AN OFFICER’S CERTIFICATE IN THE FORM
DESCRIBED IN SECTION 5.01(d) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF
COUNSEL ACCEPTABLE TO AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND
HOLDING OF A CLASS Y CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED
TRANSACTION UNDER SECTION 406 OF THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974, AS AMENDED (“ERISA”), OR SECTION
4975 OF THE CODE AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY TO ANY
OBLIGATION OR LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE) IN ADDITION
TO THOSE UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE TRUST, THE TRUSTEE, THE
DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


 


Series
2005-AR1


                                                                                                               


Cut-Off Date: January 1,
2005


First Distribution Date: February
25, 2005


Last Scheduled Distribution Date:
August 25, 2013


Deutsche Bank National Trust
Company


as Trustee for WaMu
Mortgage-Pass-Through Certificates, Series 2005-AR1 Trust

Registered Owner


 









Exhibit A

CUSIP 939336 Y7 2


WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


Class B-4


Evidencing a beneficial interest in a pool of
assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to
four-family mortgage loans formed and administered by


WASHINGTON MUTUAL
MORTGAGE SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through
Certificates Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real
estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal
Revenue Code of 1986, as amended (the “Code”). The issue date of this Certificate is January 18, 2005.


NO TRANSFER OF THIS CLASS B-4
CERTIFICATE WILL BE MADE UNLESS THE TRUSTEE HAS RECEIVED (I) AN OFFICER’S CERTIFICATE IN THE FORM DESCRIBED IN SECTION
5.01(d) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF COUNSEL ACCEPTABLE TO
AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND HOLDING OF THIS
CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED TRANSACTION UNDER
SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE, AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER
SERVICER OR THE COMPANY TO ANY OBLIGATION OR LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION
4975 OF THE CODE) IN ADDITION TO THOSE UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE
TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


THE SECURITIES REPRESENTED BY THIS
CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. THESE SECURITIES MAY NOT BE OFFERED, SOLD, TRANSFERRED,
PLEDGED OR HYPOTHECATED IN THE ABSENCE OF REGISTRATION OR THE AVAILABILITY OF AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES
ACT OF 1933 AND EXCEPT IN ACCORDANCE WITH SECTION 5.01(e) OF THE POOLING AGREEMENT.


The Class B-4 Certificates will be subordinate in right of
payment to and provide credit support to certain Classes of Certificates, as described in the Pooling Agreement.


Series
2005-AR1                                                                                    
Portion of the Class B-4 Principal Balance as of the Cut-Off Date Evidenced by this Certificate:


$20,799,000.00


Class B-4 Certificate Interest Rate:
Variable


Cut-Off Date: January 1,
2005


First Distribution Date: February
25, 2005


Last Scheduled Distribution Date:
January 25, 2045


Class B-4
Principal Balance


as of the Cut-Off Date:
$20,799,000.00


_________________

Registered Owner


 









Exhibit A

CUSIP 939336 Y8 0


 


 WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


Class B-5


Evidencing a beneficial interest in a pool of
assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to
four-family mortgage loans formed and administered by


WASHINGTON MUTUAL
MORTGAGE SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through
Certificates Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real
estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal
Revenue Code of 1986, as amended (the “Code”). The issue date of this Certificate is January 18, 2005.


NO TRANSFER OF THIS CLASS B-5
CERTIFICATE WILL BE MADE UNLESS THE TRUSTEE HAS RECEIVED (I) AN OFFICER’S CERTIFICATE IN THE FORM DESCRIBED IN SECTION
5.01(d) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF COUNSEL ACCEPTABLE TO
AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND HOLDING OF THIS
CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED TRANSACTION UNDER
SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE, AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER
SERVICER OR THE COMPANY TO ANY OBLIGATION OR LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION
4975 OF THE CODE) IN ADDITION TO THOSE UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE
TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


THE SECURITIES REPRESENTED BY THIS
CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. THESE SECURITIES MAY NOT BE OFFERED, SOLD, TRANSFERRED,
PLEDGED OR HYPOTHECATED IN THE ABSENCE OF REGISTRATION OR THE AVAILABILITY OF AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES
ACT OF 1933 AND EXCEPT IN ACCORDANCE WITH SECTION 5.01(e) OF THE POOLING AGREEMENT.


The Class B-5 Certificates will be subordinate in right of
payment to and provide credit support to certain Classes of Certificates, as described in the Pooling Agreement.


Series
2005-AR1                                                                                    
Portion of the Class B-5 Principal Balance as of the Cut-Off Date Evidenced by this Certificate:


$17,828,000.00


Class B-5 Certificate Interest Rate:
Variable


Cut-Off Date: January 1,
2005


First Distribution Date: February
25, 2005


Last Scheduled Distribution Date:
January 25, 2045


Class B-5
Principal Balance


as of the Cut-Off Date:
$17,828,000.00


_________________

Registered Owner


 


 









Exhibit A

CUSIP 939336 Y9 8


 WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


Class B-6


Evidencing a beneficial interest in a pool of
assets consisting of beneficial interests in another pool of assets consisting of, among other things, conventional one- to
four-family mortgage loans formed and administered by


WASHINGTON MUTUAL
MORTGAGE SECURITIES CORP.


This Certificate is issued by WaMu Mortgage Pass-Through
Certificates Series 2005-AR1 Trust. This Certificate represents ownership of a “regular interest” in a “real
estate mortgage investment conduit,” as those terms are defined in Sections 860G and 860D, respectively, of the Internal
Revenue Code of 1986, as amended (the “Code”). The issue date of this Certificate is January 18, 2005.


NO TRANSFER OF THIS CLASS B-6
CERTIFICATE WILL BE MADE UNLESS THE TRUSTEE HAS RECEIVED (I) AN OFFICER’S CERTIFICATE IN THE FORM DESCRIBED IN SECTION
5.01(d) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF COUNSEL ACCEPTABLE TO
AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND HOLDING OF THIS
CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED TRANSACTION UNDER
SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE, AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER
SERVICER OR THE COMPANY TO ANY OBLIGATION OR LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION
4975 OF THE CODE) IN ADDITION TO THOSE UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE
TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


THE SECURITIES REPRESENTED BY THIS
CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. THESE SECURITIES MAY NOT BE OFFERED, SOLD, TRANSFERRED,
PLEDGED OR HYPOTHECATED IN THE ABSENCE OF REGISTRATION OR THE AVAILABILITY OF AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES
ACT OF 1933 AND EXCEPT IN ACCORDANCE WITH SECTION 5.01(e) OF THE POOLING AGREEMENT.


The Class B-6 Certificates will be subordinate in right of
payment to and provide credit support to certain Classes of Certificates, as described in the Pooling Agreement.


Series
2005-AR1                                                                                    
Portion of the Class B-6 Principal Balance as of the Cut-Off Date Evidenced by this Certificate:


$11,888,073.32


Class B-6 Certificate Interest Rate:
Variable


Cut-Off Date: January 1,
2005


First Distribution Date: February
25, 2005


Last Scheduled Distribution Date:
January 25, 2045


Class B-6
Principal Balance


as of the Cut-Off Date:
$11,888,073.32


_________________

Registered Owner


 


 


                                                                                                         












Exhibit B

CUSIP 939336 Y6 4


 WaMu MORTGAGE PASS-THROUGH CERTIFICATE


Class R


Evidencing a Percentage Interest in certain distributions with
respect to a pool of conventional one- to four-family mortgage loans formed and administered by


WASHINGTON MUTUAL
MORTGAGE SECURITIES CORP.


ANY RESALE, TRANSFER OR OTHER DISPOSITION OF THIS CERTIFICATE
MAY BE MADE ONLY IF THE PROPOSED TRANSFEREE PROVIDES A TRANSFER AFFIDAVIT TO THE COMPANY AND THE TRUSTEE THAT (1) SUCH TRANSFEREE
IS NOT EITHER (A) THE UNITED STATES, ANY STATE OR POLITICAL SUBDIVISION THEREOF, ANY FOREIGN GOVERNMENT, ANY INTERNATIONAL
ORGANIZATION, OR ANY AGENCY OR INSTRUMENTALITY OF ANY OF THE FOREGOING, (B) ANY ORGANIZATION (OTHER THAN A COOPERATIVE DESCRIBED IN
SECTION 521 OF THE CODE) WHICH IS EXEMPT FROM THE TAX IMPOSED BY CHAPTER 1 OF THE CODE UNLESS SUCH ORGANIZATION IS SUBJECT TO THE
TAX IMPOSED BY SECTION 511 OF THE CODE, (C) ANY ORGANIZATION DESCRIBED IN SECTION 1381(a)(2)(C) OF THE CODE (ANY SUCH PERSON
DESCRIBED IN THE FOREGOING CLAUSES (A), (B), OR (C) BEING HEREINAFTER REFERRED TO AS A “DISQUALIFIED ORGANIZATION”), OR
(D) AN AGENT OF A DISQUALIFIED ORGANIZATION AND (2) NO PURPOSE OF SUCH TRANSFER IS TO ENABLE THE TRANSFER TO IMPEDE THE ASSESSMENT
OR COLLECTION OF TAX. SUCH AFFIDAVIT SHALL INCLUDE CERTAIN REPRESENTATIONS AS TO THE FINANCIAL CONDITION OF THE PROPOSED
TRANSFEREE. NOTWITHSTANDING THE REGISTRATION IN THE CERTIFICATE REGISTER OF ANY TRANSFER, SALE OR OTHER DISPOSITION OF THIS CLASS R
CERTIFICATE TO A DISQUALIFIED ORGANIZATION OR AN AGENT OF A DISQUALIFIED ORGANIZATION, SUCH REGISTRATION SHALL BE DEEMED TO BE OF
NO LEGAL FORCE OR EFFECT WHATSOEVER AND SUCH PERSON SHALL NOT BE DEEMED TO BE A CERTIFICATEHOLDER FOR ANY PURPOSE HEREUNDER,
INCLUDING, BUT NOT LIMITED TO, THE RECEIPT OF DISTRIBUTIONS ON THIS CERTIFICATE. EACH HOLDER OF A CLASS R CERTIFICATE BY ACCEPTANCE
OF THIS CERTIFICATE SHALL BE DEEMED TO HAVE CONSENTED TO THE PROVISIONS OF THIS PARAGRAPH.


IN THE CASE OF ANY CLASS R CERTIFICATE PRESENTED FOR
REGISTRATION IN THE NAME OF ANY PERSON, THE TRUSTEE SHALL REQUIRE (I) AN OFFICER’S CERTIFICATE IN THE FORM DESCRIBED IN
SECTION 5.01(d) OF THE POOLING AGREEMENT AND (II) IF SO INDICATED IN SUCH OFFICER’S CERTIFICATE, AN OPINION OF COUNSEL
ACCEPTABLE TO AND IN FORM AND SUBSTANCE SATISFACTORY TO THE TRUSTEE AND THE COMPANY TO THE EFFECT THAT THE PURCHASE AND HOLDING OF
A CLASS R CERTIFICATE ARE PERMISSIBLE UNDER APPLICABLE LAW, WILL NOT CONSTITUTE OR RESULT IN A NON-EXEMPT PROHIBITED TRANSACTION
UNDER SECTION 406 OF THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974, AS AMENDED (“ERISA”), OR SECTION 4975 OF THE
CODE AND WILL NOT SUBJECT THE TRUST, THE TRUSTEE, THE DELAWARE TRUSTEE, THE MASTER SERVICER OR THE COMPANY TO ANY OBLIGATION OR
LIABILITY (INCLUDING OBLIGATIONS OR LIABILITIES UNDER SECTION 406 OF ERISA OR SECTION 4975 OF THE CODE) IN ADDITION TO THOSE
UNDERTAKEN IN THE POOLING AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE TRUST, THE TRUSTEE, THE DELAWARE
TRUSTEE, THE MASTER SERVICER OR THE COMPANY.


This Certificate is issued by WaMu Mortgage Pass-Through
Certificates Series 2005-AR1 Trust. Solely for U.S. federal income tax purposes, this Certificate represents “residual
interests” in “real estate mortgage investment conduits,” as those terms are defined in Sections 860G and 860D,
respectively, of the Internal Revenue Code of 1986, as amended.


Series
2005-AR1                                                                                    
Percentage Interest evidenced by this Class R Certificate in the distributions to be made with respect to the Class R Certificates:
___%


Class R Certificate Interest Rate: _____%.  Additionally the Class R Certificates are entitled to Excess
Liquidation Proceeds and the Residual Distribution Amount as defined in the Pooling Agreement.


Cut-Off Date: January 1,
2005


First Distribution Date: February
25, 2005


Last Scheduled Distribution Date:
January 25, 2045


Class R Principal Balance as of the
Cut-Off Date: $100.00


___________________

Registered Owner


Certificate No.
__







This Certificate does not represent an
obligation of or interest in Washington Mutual Mortgage Securities Corp. or any of its affiliates. Neither this Certificate nor the
underlying Mortgage Loans are guaranteed by any agency or instrumentality of the United States.


This certifies that the above-named
Registered Owner is the registered owner of certain interests in (i) a pool of assets (“REMIC I”) consisting of, among
other things, conventional one- to four-family mortgage loans (the “Mortgage Loans”), formed and administered by
Washington Mutual Mortgage Securities Corp. (the “Company”), which term includes any successor entity under the Pooling
Agreement referred to below, and (ii) a pool of assets (“REMIC II”) consisting of interests in REMIC I. REMIC I and
REMIC II were created pursuant to a Pooling and Servicing Agreement, dated as of the Cut-Off Date stated above (the “Pooling
Agreement”), among the Company, Deutsche Bank National Trust Company, as Trustee (the “Trustee”), and Deutsche
Bank Trust Company Delaware, as Delaware Trustee, a summary of certain of the pertinent provisions of which is set forth hereafter.
To the extent not defined herein, the capitalized terms used herein have the meanings assigned in the Pooling Agreement. Nothing
herein shall be deemed inconsistent with such meanings, and in the event of any conflict between the Pooling Agreement and the
terms of this Certificate, the Pooling Agreement shall control. This Certificate is issued under and is subject to the terms,
provisions and conditions of the Pooling Agreement, to which Pooling Agreement the Holder of this Certificate, by virtue of the
acceptance hereof, assents and by which such Holder is bound.


Distributions will be made, pursuant to
the Pooling Agreement, on the 25th day of each month or, if such 25th day is not a Business Day, the Business Day immediately
following (the “Distribution Date”), commencing on the first Distribution Date specified above, to the Person in whose
name this Certificate is registered at the close of business on the last day (or if such last day is not a Business Day, the
Business Day immediately preceding such last day) of the month immediately preceding the month of such distribution (the
“Record Date”), to the extent of such Certificateholder's Percentage Interest represented by this Certificate in the
portions (if any) then distributable on the Certificates of this Class of (i) the REMIC I Available Distribution Amount for such
Distribution Date, as specified in Section 4.01 of the Pooling Agreement and (ii) the REMIC II Available Distribution Amount for
such Distribution Date, as specified in Section 4.04 of the Pooling Agreement.


Distributions on this Certificate will
be made by the Trustee by wire transfer or check mailed to the address of the Person entitled thereto, as such name and address
shall appear on the Certificate Register. Notwithstanding the above, the final distribution on this Certificate will be made after
due notice by the Trustee of the pendency of such distribution and only upon presentation and surrender of this Certificate to the
Certificate Registrar.


Reference is hereby made to the further
provisions of this Certificate set forth below, which further provisions shall for all purposes have the same effect as if set
forth at this place.


Unless the certificate of
authentication hereon has been executed by or on behalf of the Trustee, by manual signature, this Certificate shall not be entitled
to any benefit under the Pooling Agreement or be valid for any purpose.







IN WITNESS WHEREOF, the Trust has
caused this Certificate to be duly executed.


WaMu MORTGAGE PASS-THROUGH
CERTIFICATES SERIES 2005-AR1 TRUST


 


By:    DEUTSCHE BANK NATIONAL TRUST COMPANY, as Trustee


 


By:
                                                                          


 


 


(TRUSTEE'S CERTIFICATE
OF AUTHENTICATION)


This is one of the Certificates
referred to in the within-mentioned Pooling Agreement.


DEUTSCHE BANK
NATIONAL TRUST COMPANY,


as Trustee


 


By:
                                                     


Dated:
                                                







WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.


WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


This Certificate is one of a duly authorized issue of Certificates
designated as WaMu Mortgage Pass-Through Certificates of the Series and Class specified hereon (herein called the
“Certificates”) and representing certain interests in REMIC I and REMIC II.


The Certificates do not represent an obligation of, or an interest in,
the Company or any of its affiliates and are not insured or guaranteed by any governmental agency. The Certificates are limited in
right of payment to certain collections and recoveries respecting the Mortgage Loans, all as more specifically set forth herein and
in the Pooling Agreement. In the event funds are advanced with respect to any Mortgage Loan, such advance is reimbursable to the
Master Servicer from the related recoveries on such Mortgage Loan or from other cash deposited in the Certificate Account to the
extent that such advance is not otherwise recoverable.


As provided in the Pooling Agreement, withdrawals from the Certificate
Account may be made from time to time for purposes other than distributions to Certificateholders, such purposes including
reimbursement to the Master Servicer of advances made, or certain expenses incurred, by it.


The Pooling Agreement permits, with certain exceptions therein
provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of the
Certificateholders under the Pooling Agreement at any time by the Company, the Master Servicer and the Trustee with the consent of
the Holders of the Certificates evidencing Percentage Interests aggregating not less than 66% of REMIC II. The Pooling Agreement
also permits the amendment thereof, in certain limited circumstances, without the consent of the Holders of any of the
Certificates.


As provided in the Pooling Agreement and subject to certain
limitations therein set forth, the transfer of this Certificate is registrable in the Certificate Register upon surrender of this
Certificate for registration of transfer at the offices of the Certificate Registrar or the office maintained by the Trustee in the
City and State of New York, duly endorsed by, or accompanied by an assignment in the form below or other written instrument of
transfer in form satisfactory to the Trustee or any Authenticating Agent duly executed by, the Holder hereof or such Holder's
attorney duly authorized in writing, and thereupon one or more new Certificates of Authorized Denominations evidencing the same
Percentage Interest set forth hereinabove will be issued to the designated transferee or transferees.


The Certificates are issuable only as registered Certificates without
coupons in Authorized Denominations specified in the Pooling Agreement. As provided in the Pooling Agreement and subject to certain
limitations therein set forth, Certificates are exchangeable for new Certificates of Authorized Denominations of like Certificate
Principal Balance or Percentage Interest, as applicable, as requested by the Holder surrendering the same.


A reasonable service charge may be made for any such registration of
transfer or exchange, and the Trustee may require payment of a sum sufficient to cover any tax or other governmental charge payable
in connection therewith.


The Company, the Trustee and the Certificate Registrar and any agent
of the Company, the Trustee or the Certificate Registrar may treat the Person in whose name this Certificate is registered as the
owner hereof for all purposes, and neither the Company, the Trustee, the Certificate Registrar nor any such agent shall be affected
by notice to the contrary.


The obligations created by the Pooling Agreement and the Trust created
thereby shall terminate upon (i) the later of the maturity or other liquidation (including purchase by the Master Servicer) of the
last Mortgage Loan remaining in the Trust or the disposition of all property acquired upon foreclosure or deed in lieu of
foreclosure of any Mortgage Loan, and (ii) the payment to Certificateholders of all amounts held by the Trustee and required to be
paid to them pursuant to the Pooling Agreement. In the event that the Company or the Master Servicer purchases any Mortgage Loan
pursuant to the Pooling Agreement, the Pooling Agreement generally requires that the Trustee distribute to the Certificateholders
in the aggregate an amount equal to 100% of the unpaid Principal Balance of such Mortgage Loan, plus unpaid accrued interest
thereon at the applicable Pass-Through Rate to the last day of the month in which such purchase occurs. The Pooling Agreement
permits, but does not require, the Master Servicer to purchase from the Trust all Mortgage Loans at the time subject thereto and
all property acquired in respect of any Mortgage Loan upon payment to the Certificateholders of the amounts specified in the
Pooling Agreement. The exercise of such right will effect early retirement of the Certificates, the Master Servicer’s right
to purchase being subject to the aggregate Principal Balance of the Mortgage Loans at the time of purchase being less than the
Clean-Up Call Percentage of the aggregate Principal Balance of the Mortgage Loans as of the Cut-Off Date.







ASSIGNMENT


 


FOR VALUE RECEIVED the undersigned hereby sell(s) and assign(s) and transfer(s) unto


                                                                                                                                                                                                                    


                                                                                                                                                                                                                    


(Please print or typewrite name and address, including postal zip code of assignee. Please insert social security or other
identifying number of assignee.)


the within WaMu
Mortgage Pass-Through Certificate and hereby irrevocably constitutes and appoints


                                                                                                                                                                                                                    


Attorney to transfer said Certificate on the
Certificate Register, with full power of substitution in the premises.


Dated:
                        
           
                                                                                                           


Signature Guaranteed


                                                                                                           


 NOTICE:    The signature to this assignment must correspond with
the name as written upon the face of the within instrument in every particular, without alteration or enlargement or any change
whatever.  This Certificate does not represent an obligation of or an interest in Washington Mutual Mortgage Securities Corp.
or any of its affiliates.  Neither this Certificate nor the underlying Mortgage Loans are guaranteed by any agency or
instrumentality of the United States.










Exhibit C


ANTI-PREDATORY LENDING
CATEGORIZATION


 


I.              High-Cost Loan Categorization


	
State/Jurisdiction

	
Name of Anti-Predatory Lending
Law/Effective Date

	
Category under Applicable

Anti-Predatory Lending Law

 


	
Arkansas

	
Arkansas Home Loan Protection Act, Ark.
Code Ann. §§ 23-53-101 et seq.


Effective July 16, 2003

	
High Cost Home Loan


	
Cleveland Heights, OH

	
Ordinance No. 72-2003 (PSH), Mun. Code §§ 757.01 et seq.


Effective June 2, 2003

	
Covered Loan


	
Colorado

	
Consumer Equity Protection, Colo. Stat. Ann.
§§ 5-3.5-101 et seq.


Effective for covered loans offered or entered
into on or after January 1, 2003. Other provisions of the Act took effect on June 7, 2002

	
Covered Loan


	
Connecticut

	
Connecticut Abusive Home Loan Lending Practices
Act, Conn. Gen. Stat. §§ 36a-746 et seq.


Effective October 1, 2001

	
High Cost Home Loan


	
District of Columbia

	
Home Loan Protection Act, D.C. Code
§§ 26-1151.01 et seq.


Effective for loans closed on or after January
28, 2003

	
Covered Loan


	
Florida

	
Fair Lending Act, Fla. Stat. Ann. §§ 494.0078 et seq.


Effective October 2, 2002

	
High Cost Home Loan


	
Georgia (Oct 1, 2002 – Mar 6, 2003)

	
Georgia Fair Lending Act, Ga. Code Ann. §§ 7-6A-1 et seq.


Effective October 1, 2002 – March 6,
2003

	
High Cost Home Loan


	
Georgia as amended (Mar 7, 2003 – current)

	
Georgia Fair Lending Act, Ga. Code Ann. §§ 7-6A-1 et seq.


Effective for loans closed on or after March 7,
2003

	
High Cost Home Loan


	
HOEPA Section 32

	
Home Ownership and Equity Protection Act of
1994, 15 U.S.C. § 1639, 12 C.F.R. §§ 226.32 and 226.34


Effective October 1, 1995, amendments October
1, 2002

	
High Cost Loan


	
Illinois

	
High Risk Home Loan Act, Ill. Comp. Stat. tit. 815, §§ 137/5 et seq.


Effective January 1, 2004 (prior to this date,
regulations under Residential Mortgage License Act effective from May 14, 2001)

	
High Risk Home Loan


	
Kansas

	
Consumer Credit Code, Kan. Stat. Ann. §§ 16a-1-101 et seq.


Sections 16a-1-301 and 16a-3-207 became
effective April 14, 1999; Section 16a-3-308a became effective July 1, 1999

	
High Loan to Value Consumer Loan (id. § 16a-3-207) and;


 


High APR Consumer Loan (id. § 16a-3-308a)


 


	
Kentucky

	
2003 KY H.B. 287 – High Cost Home Loan
Act, Ky. Rev. Stat. §§ 360.100 et seq.


Effective June 24, 2003

	
High Cost Home Loan


	
Maine

	
Truth in Lending, Me. Rev. Stat. tit. 9-A,
§§ 8-101 et seq.


Effective September 29, 1995 and as amended
from time to time

	
High Rate High Fee Mortgage


	
Massachusetts

	
Part 40 and Part 32, 209 C.M.R. §§
32.00 et seq. and 209 C.M.R. §§ 40.01 et seq.


Effective March 22, 2001 and amended from time
to time

	
High Cost Home Loan


	
Nevada

	
Assembly Bill No. 284, Nev. Rev. Stat. §§ 598D.010 et seq.


Effective October 1, 2003

	
Home Loan


	
New Jersey

	
New Jersey Home Ownership Security Act of 2002,
N.J. Rev. Stat. §§ 46:10B-22 et seq.


Effective for loans closed on or after November
27, 2003

	
High Cost Home Loan


	
New York

	
Home Loan Protection Act, N.M. Rev.
Stat. §§ 58-21A-1 et seq.


Effective as of January 1, 2004; Revised as of
February 26, 2004

	
High Cost Home Loan


	
New Mexico

	
N.Y. Banking Law Article 6-l


Effective for applications made on or after
April 1, 2003

	
High Cost Home Loan


	
North Carolina

	
Restrictions and Limitations on High Cost Home
Loans, N.C. Gen. Stat. §§ 24-1.1E et seq.


Effective July 1, 2000; amended October 1, 2003
(adding open-end lines of credit)

	
High Cost Home Loan


	
Ohio

	
H.B. 386 (codified in various sections of the
Ohio Code), Ohio Rev. Code Ann. §§ 1349.25 et seq.


Effective May 24, 2002

	
Covered Loan


	
Oklahoma

	
Consumer Credit Code (codified in various
sections of Title 14A)


Effective July 1, 2000; amended effective
January 1, 2004

	
Subsection 10 Mortgage


	
South Carolina

	
South Carolina High Cost and Consumer Home
Loans Act, S.C. Code Ann. §§ 37-23-10 et seq.


Effective for loans taken on or after January
1, 2004

	
High Cost Home Loan


	
West Virginia

	
West Virginia Residential Mortgage Lender,
Broker and Servicer Act, W. Va. Code Ann. §§ 31-17-1 et seq.


Effective June 5, 2002

	
West Virginia Mortgage Loan Act Loan





 


II.            Covered
Loan Categorization


                                                                               
                    


	
State/Jurisdiction

	
Name of Anti-Predatory Lending
Law/Effective Date

	
Category under Applicable

Anti-Predatory Lending Law

 


	
Georgia (Oct 1, 2002 – Mar 6, 2003)

	
Georgia Fair Lending Act, Ga. Code Ann. §§ 7-6A-1 et seq.


Effective October 1, 2002 – March 6,
2003

	
Covered Loan


	
New Jersey

	
New Jersey Home Ownership Security Act of 2002,
N.J. Rev. Stat. §§ 46:10B-22 et seq.


Effective November 27, 2003 – July 5,
2004

	
Covered Home Loan





 


 












Exhibit D


Mortgage Loan
Schedule


 


Copies of the Mortgage Loan Schedule (which has been intentionally
omitted from this filing) may be obtained from Washington Mutual Mortgage Securities Corp. or Deutsche Bank National Trust Company
by contacting:


	
 

	
      in the case of Washington Mutual
Mortgage Securities Corp.,





 


	
 

	
        Laura Kelsey

         Master Servicing Department

         Washington Mutual Mortgage Securities Corp.

         75 N. Fairway Drive,VHF2A01

          Vernon Hills, IL 60061

         Telephone:  (847) 393-5198

         Facsimile:     (847) 549-2997





 


	
 

	
      in the case of Deutsche Bank
National Trust Company,





 


	
 

	
        Alan Sueda

         Trust Administrator

         Deutsche Bank National Trust Company

         1761 E. St. Andrew Place

         Santa Ana, CA 92705

         Telephone:  (714) 247-6315

         Facsimile:    (714) 247-6329





 


 












Exhibit E






SELLING AND
SERVICING


CONTRACT



 


This Selling and
Servicing Contract (this “Agreement”) is made and entered into by Washington Mutual Mortgage Securities Corp. and its
successors and assigns (“Washington Mutual Mortgage”) and the entity identified below and its successors and assigns
(the “Company”).


 


WITNESSETH:


            WHEREAS, this Company wishes to sell first lien
residential mortgage loans to, and service first lien residential mortgage loans on behalf of, Washington Mutual Mortgage;
and


            WHEREAS, the Company has submitted a Seller Application to Washington Mutual Mortgage and has been approved by Washington Mutual
Mortgage for participation in the Washington Mutual Mortgage Purchase Programs; and


            WHEREAS, the Company has received and reviewed the Washington Mutual Mortgage Purchase Programs Seller Guide (the “Seller
Guide”), as well as the Washington Mutual Mortgage Servicing Guide (the “Servicing Guide” and, together with the
Seller Guide, the “Guides”), and understands each and every provision thereof;


            NOW, THEREFORE, in consideration of the premises and of the mutual agreements herein contained, Washington Mutual Mortgage and the Company
hereby agree as follows:


            1.        
Guides.  The Guides, which set forth the terms and conditions under which Washington Mutual Mortgage may elect to
purchase mortgage loans from the Company, and the Company shall service mortgage loans on behalf of Washington Mutual Mortgage, are
a supplement to this Agreement and such Guides, as may be amended or supplemented from time to time by Washington Mutual Mortgage,
are incorporated into this Agreement in full by reference and made a part hereof as fully as if set forth at length herein. 
All capitalized terms used and not defined herein have the meanings ascribed to them in the Guides.


            2.        
Company’s Duties.  The Company shall diligently perform all duties incident to the origination, sale and servicing
of the mortgage loans subject to this Agreement.  In the performance of its servicing duties, the Company shall exercise the
same degree of care it exercises when servicing mortgage loans for its own account, but in no event shall the Company exercise less
care than a reasonable prudent servicer would exercise under similar circumstances.  In addition, the Company shall comply
with all of the provisions of the Guides and with all other requirements and instructions of Washington Mutual Mortgage.  The
Company shall perform such duties at its sole expense, except as otherwise expressly provided in the Guides.


            3.        
Representations, Warranties and Covenants of the Company; Remedies of Washington Mutual Mortgage.  With respect to each
mortgage loan sold by the Company to Washington Mutual Mortgage pursuant to the terms of this Agreement, the Company shall make all
of the representations, warranties and covenants set forth in the Guide and, in the event of the breach of any of such
representations, warranties and covenants, Washington Mutual Mortgage shall have all of the remedies available at law or in equity,
as well as all of the remedies set forth in the Guide, including, but not limited to, repurchase and indemnification.  The
representations and warranties made by the Company with respect to any mortgage loan subject to this Agreement, as well as the
remedies available to Washington Mutual Mortgage upon the breach thereof, shall survive:  (a) any investigation regarding the
mortgage loan conducted by Washington Mutual Mortgage, its assignees or designees, (b) the liquidation of the mortgage loan, (c)
the purchase of the mortgage loan by Washington Mutual Mortgage, its assignee or designee, (d) the repurchase of the mortgage loan
by the Company and (e) the termination of this Agreement.


            4.        
Compensation.  The Company shall be compensated for its services hereunder as specified in the Guides.


            5.         No
Assignment.  This Agreement may not be assigned by the Company without the prior written consent of Washington Mutual
Mortgage.  The Company hereby consents to the assignment by Washington Mutual Mortgage of all or any part of its rights and
obligations under this Agreement to any affiliate designated by Washington Mutual Mortgage.  Any other transfer by Washington
Mutual Mortgage will be allowed and be effective upon written notice by Washington Mutual Mortgage to the Company.


            6.        
Prior Agreements.  This Agreement supersedes any prior agreements and understandings between Washington Mutual Mortgage
and the Company governing the subject matter hereof; provided, however, the Company shall not be released from any responsibility
or liability that may have arisen under such agreements and understanding.


            7.        
Effective Date of Agreement.  This Agreement is not effective until it is executed and accepted by Washington Mutual
Mortgage at its home office in Illinois.


            8.        
Notices.  All notices, requests, demands or other communications that are to be given under this Agreement shall be in
writing, addressed to the appropriate parties, and shall be sent by certified mail, return receipt requested, postage prepaid, if
to the Company, at the address below and, if to Washington Mutual Mortgage, to the appropriate address or facsimile number
specified in the Guides.  Any such notice, request, demand or other communication shall be deemed effective upon
receipt.


            9.        
Independent Contractor.  At no time shall the Company represent that it is acting as an agent, partner or joint
venturer of Washington Mutual Mortgage.  The Company shall at all times act as an independent contracting party.


            10.       
Amendment.  This Agreement may not be amended or modified orally, and no provision of this Agreement may be waived or
amended, except in writing signed by the party against whom enforcement is sought.  Such a written waiver or amendment must
expressly reference this Agreement.  However, by their terms the Guides may be amended or supplemented by Washington Mutual
Mortgage from time to time.  Any such amendment(s) to the Guides shall be in writing and be binding upon the parties hereto on
and after the effective date specified therein.


            11.       
Miscellaneous.  This Agreement, including all documents incorporated by reference herein, constitutes the entire
understanding between the parties hereto and supersedes all other agreements, covenants, representations, warranties,
understandings and communications between the parties, whether written or oral, with respect to the transactions contemplated by
this Agreement.  All section headings contained herein are for convenience only and shall not be construed as part of this
Agreement.  Any provision of this Agreement that is prohibited or unenforceable in any jurisdiction shall as to such
jurisdiction be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining portions
hereof or affecting the validity or enforceability of such provision in any other jurisdiction, and to this end, the provisions
hereof are severable.  This Agreement shall be governed by, and construed and enforced in accordance with, applicable federal
laws and laws of the State of Illinois, without reference to conflict of laws principles. This Agreement may be executed in one or
more counterparts, each of which shall constitute an original and all of which shall constitute the same Agreement.


            IN WITNESS WHEREOF, the parties have executed this
Agreement by proper officials duly authorized on the dates hereinafter set forth.  This Agreement shall take effect as of the
date of its execution in original or facsimile signature by a duly authorized officer of Washington Mutual Mortgage.


 


	
__________________________________________

	
___________________________________


	
Name of the
Company

	
Company I.D.
Number


	
__________________________________________

	
___________________________________


	
Type of
organization

	
Organized under laws
of


	
________________________________________________________________________________


	
Principal place of
business:  street address, city, state, zip code


	
________________________________________________________________________________


	
Typed name and title of
the Company’s authorized officer


	
_______________________________________________________

	
_______________________


	
Signature of the
Company’s authorized officer

	
Date


	
 


Agreed to and
accepted by Washington Mutual Mortgage Securities Corp.


	
________________________________________________________________________________


	
Typed name and title of
authorized representative


	
_______________________________________________________

	
_______________________


	
Signature of authorized
representative

	
Date


			



 


 












              Exhibit F






FORM OF TRANSFEROR CERTIFICATE FOR


JUNIOR SUBORDINATE CERTIFICATES


 


[Date]


Deutsche Bank
National Trust Company, as Trustee

1761 East St. Andrew Place

Santa Ana, CA 92705

Attn: Trust Administration WA05A1 


Re:       Purchase of Washington Mutual Mortgage Securities Corp. WaMu Mortgage Pass-Through
Certificates Series 2005-AR1, Class [   ]  (the “Certificates”)


Ladies and Gentlemen:


In connection with our disposition of
the above Certificates we certify that (a) we understand the Certificates have not been registered under the Securities Act of
1933, as amended (the “Act”) and are being disposed by us in a transaction that is exempt from the registration
requirements of the Act, and (b) we have not offered or sold any certificates to, or solicited offers to buy any Certificates from,
any person, or otherwise approached or negotiated with any person with respect thereto, or taken any other action which would
result in a violation of Section 5 of the Act.


 


Very truly yours,


[Name of Transferor]


 



By:                                                      


                   Authorized
Officer


 












             Exhibit G






FORM OF TRANSFEREE'S AGREEMENT FOR


JUNIOR SUBORDINATE
CERTIFICATES


[Date]


Deutsche Bank
National Trust Company, as Trustee

1761 East St. Andrew Place

Santa Ana, CA 92705

Attn: Trust Administration WA05A1


Washington
Mutual Mortgage Securities Corp.

75 N. Fairway Drive

Vernon Hills, Illinois  60061 


The undersigned (the
“Purchaser”) proposes to purchase Washington Mutual Mortgage Securities Corp. WaMu Mortgage Pass-Through Certificates,
Series 2005-AR1, Class [   ] (the “Purchased Certificates”) in the principal amount of $______________. In
doing so, the Purchaser hereby acknowledges and agrees as follows:


Section 1. Definitions. Each
capitalized term used herein and not otherwise defined herein shall have the meaning ascribed to it in the Pooling and Servicing
Agreement, dated as of January 1, 2005 (the “Pooling Agreement”), by and among Washington Mutual Mortgage Securities
Corp. (“Washington Mutual”), Deutsche Bank National Trust Company, as trustee (the “Trustee”), and Deutsche
Bank Trust Company Delaware, as Delaware trustee, of the Washington Mutual Mortgage Securities Corp. WaMu Mortgage Pass-Through
Certificates, Series 2005-AR1.


Section 2. Representations and
Warranties of the Purchaser. In connection with the proposed transfer, the Purchaser represents and warrants to Washington Mutual,
the Trustee and the Trust that:


(a)        The Purchaser is duly organized, validly existing and in good standing under
the laws of the jurisdiction in which the Purchaser is organized, is authorized to invest in the Purchased Certificates, and to
enter into this Agreement, and duly executed and delivered this Agreement;


(b)        The Purchaser is acquiring the Purchased Certificates for its own account as
principal and not with a view to the distribution thereof, in whole or in part;


(c)        The Purchaser is an “accredited investor” as such term is defined
in paragraph (a)(1), (a)(2), (a)(3), (a)(7) or (a)(8) of Section 501 of Regulation D under the Securities Act of 1933, as amended
(the “Act”), has knowledge of financial and business matters and is capable of evaluating the merits and risks of an
investment in the Purchased Certificates; the Purchaser has sought such accounting, legal and tax advice as it has considered
necessary to make an informed investment decision; and the Purchaser is able to bear the economic risk of an investment in the
Purchased Certificates and can afford a complete loss of such investment;


(d)        The Purchaser is not affiliated with the Trustee;


(e)        The Purchaser confirms that Washington Mutual has made available to the
Purchaser the opportunity to ask questions of, and receive answers from Washington Mutual concerning the trust created pursuant to
the Pooling Agreement (the “Trust”), the purchase by the Purchaser of the Purchased Certificates and all matters
relating thereto that Washington Mutual possesses or can acquire without unreasonable effort or expense; and


(f)        If applicable, the Purchaser has complied, and will continue to comply, with
the guidelines established by Thrift Bulletin 13a issued April 23, 1998, by the Office of Regulatory Activities of the Federal Home
Loan Bank System.


Section 3. Transfer of Purchased
Certificates.


(a)        The Purchaser understands that the Purchased Certificates have not been
registered under the Act, or any state securities laws and that no transfer may be made unless the Purchased Certificates are
registered under the Act and under applicable state law or unless an exemption from registration is available. The Purchaser
further understands that neither Washington Mutual nor the Trust is under any obligation to register the Purchased Certificates or
make an exemption available. In the event that such a transfer is to be made within two years from the Closing Date without
registration under the Act or applicable state securities laws, (i) the Trustee shall require, in order to assure compliance with
such laws, that the Certificateholder's prospective transferee each certify to Washington Mutual, the Trustee and the Trust as to
the factual basis for the registration or qualification exemption relied upon, and (ii) the Trustee or Washington Mutual may
require an Opinion of Counsel that such transfer may be made pursuant to an exemption from the Act and state securities laws, which
Opinion of Counsel shall not be an expense of the Trust, the Trustee or Washington Mutual. Any such Certificateholder desiring to
effect such transfer shall, and does hereby agree to, indemnify the Trust, the Trustee and Washington Mutual against any liability
that may result if the transfer is not so exempt or is not made in accordance with such federal and state laws.


(b)        No transfer of a Purchased Certificate shall be made unless the transferee
provides Washington Mutual and the Trustee with (i) a Transferee's Agreement, substantially in the form of this Agreement, (ii) an
affidavit substantially in the form of Exhibit N to the Pooling Agreement and (iii) if so indicated in such affidavit, a Benefit
Plan Opinion (as defined in Section 1.01 of the Pooling Agreement).


(c)        The Purchaser acknowledges that its Purchased Certificates bear a legend
setting forth the applicable restrictions on transfer.


IN WITNESS WHEREOF, the undersigned
has caused this Agreement to be validly executed by its duly authorized representative as of the day and the year first above
written.



[Purchaser]


 



 



By:
                                                                 


Its:


 


 












             Exhibit H-1






FORM OF ADDITIONAL MATTER INCORPORATED INTO

THE FORM OF THE CERTIFICATES

(OTHER THAN THE CLASS R AND CLASS Y CERTIFICATES)


This Certificate does not represent an
obligation of or interest in Washington Mutual Mortgage Securities Corp. or any of its affiliates. Neither this Certificate nor the
underlying Mortgage Loans are guaranteed by any agency or instrumentality of the United States.


This certifies that the above-named
Registered Owner is the registered owner of certain interests in a pool of assets (“REMIC II”) consisting of interests
in another pool of assets (“REMIC I”) consisting of, among other things, conventional one- to four-family mortgage
loans (the “Mortgage Loans”), formed and administered by Washington Mutual Mortgage Securities Corp. (the
“Company”), which term includes any successor entity under the Pooling Agreement referred to below. REMIC I and REMIC
II were created pursuant to a Pooling and Servicing Agreement, dated as of the Cut-Off Date stated above (the “Pooling
Agreement”), among the Company, Deutsche Bank National Trust Company, as Trustee (the “Trustee”), and Deutsche
Bank Trust Company Delaware, as Delaware Trustee, a summary of certain of the pertinent provisions of which is set forth hereafter.
To the extent not defined herein, the capitalized terms used herein have the meanings assigned in the Pooling Agreement. Nothing
herein shall be deemed inconsistent with such meanings, and in the event of any conflict between the Pooling Agreement and the
terms of this Certificate, the Pooling Agreement shall control. This Certificate is issued under and is subject to the terms,
provisions and conditions of the Pooling Agreement, to which Pooling Agreement the Holder of this Certificate, by virtue of the
acceptance hereof, assents and by which such Holder is bound.


Distributions will be made, pursuant to
the Pooling Agreement, on the 25th day of each month or, if such 25th day is not a Business Day, the Business Day immediately
following (the “Distribution Date”), commencing on the first Distribution Date specified above, to the Person in whose
name this Certificate is registered at the close of business on the last day (or if such last day is not a Business Day, the
Business Day immediately preceding such last day) of the month immediately preceding the month of such distribution (the
“Record Date”), to the extent of such Certificateholder's Percentage Interest represented by this Certificate in the
portion of the REMIC II Available Distribution Amount for such Distribution Date then distributable on the Certificates of this
Class, as specified in Section 4.04 of the Pooling Agreement.


Distributions on this Certificate will
be made by the Trustee by wire transfer or check mailed to the address of the Person entitled thereto, as such name and address
shall appear on the Certificate Register. Notwithstanding the above, the final distribution on this Certificate will be made after
due notice by the Trustee of the pendency of such distribution and only upon presentation and surrender of this Certificate to the
Certificate Registrar.


Reference is hereby made to the further
provisions of this Certificate set forth below, which further provisions shall for all purposes have the same effect as if set
forth at this place.


Unless the certificate of
authentication hereon has been executed by or on behalf of the Trustee, by manual signature, this Certificate shall not be entitled
to any benefit under the Pooling Agreement or be valid for any purpose.







IN WITNESS WHEREOF, the Trust has
caused this Certificate to be duly executed.


WaMu MORTGAGE PASS-THROUGH
CERTIFICATES SERIES 2005-AR1 TRUST


 


By:    DEUTSCHE BANK NATIONAL TRUST COMPANY, as Trustee


 


By:
                                                                          


 


 


(TRUSTEE'S CERTIFICATE
OF AUTHENTICATION)


This is one of the Certificates
referred to in the within-mentioned Pooling Agreement.


DEUTSCHE BANK
NATIONAL TRUST COMPANY,


as Trustee


 


By:
                                                     


Dated:
                                                


 







WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.


 WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


This Certificate is one of a duly authorized issue of Certificates
designated as WaMu Mortgage Pass-Through Certificates of the Series and Class specified hereon (herein called the
“Certificates”) and representing certain interests in REMIC II [to be used only in the case of the Class A
Certificates, other than the Class A-3 Certificates:][, together with certain rights specified in the Pooling Agreement][to be
used only in the case of the Class X Certificates:][, together with certain obligations specified in the Pooling
Agreement].


The Certificates do not represent an obligation of, or an interest in,
the Company or any of its affiliates and are not insured or guaranteed by any governmental agency. The Certificates are limited in
right of payment to certain collections and recoveries respecting the Mortgage Loans, all as more specifically set forth herein and
in the Pooling Agreement. In the event funds are advanced with respect to any Mortgage Loan, such advance is reimbursable to the
Master Servicer from the related recoveries on such Mortgage Loan or from other cash deposited in the Certificate Account to the
extent that such advance is not otherwise recoverable.


As provided in the Pooling Agreement, withdrawals from the Certificate
Account may be made from time to time for purposes other than distributions to Certificateholders, such purposes including
reimbursement to the Master Servicer of advances made, or certain expenses incurred, by it.


The Pooling Agreement permits, with certain exceptions therein
provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of the
Certificateholders under the Pooling Agreement at any time by the Company, the Master Servicer and the Trustee with the consent of
the Holders of the Certificates evidencing Percentage Interests aggregating not less than 66% of REMIC II. Any such consent by the
Holder of this Certificate shall be conclusive and binding on such Holder and upon all future Holders of this Certificate and of
any Certificate issued upon the transfer hereof or in exchange herefor or in lieu hereof whether or not notation of such consent is
made upon this Certificate. The Pooling Agreement also permits the amendment thereof, in certain limited circumstances, without the
consent of the Holders of any of the Certificates.


As provided in the Pooling Agreement and subject to certain
limitations therein set forth, the transfer of this Certificate is registrable in the Certificate Register upon surrender of this
Certificate for registration of transfer at the offices of the Certificate Registrar or the office maintained by the Trustee in the
City and State of New York, duly endorsed by, or accompanied by an assignment in the form below or other written instrument of
transfer in form satisfactory to the Trustee or any Authenticating Agent duly executed by, the Holder hereof or such Holder's
attorney duly authorized in writing, and thereupon one or more new Certificates of Authorized Denominations evidencing the same
Percentage Interest set forth hereinabove will be issued to the designated transferee or transferees.


[to be used only in the case of the Junior Subordinate Certificates:]
[No transfer of a Certificate will be made unless such transfer is exempt from or is made in accordance with the registration
requirements of the Securities Act of 1933, as amended (the “Securities Act”) and any applicable state securities laws.
In the event that a transfer is to be made without registration or qualification under applicable laws, (i) in the event such
transfer is made pursuant to Rule 144A under the Securities Act, the Company and the Trustee shall require the transferee to
execute an investment letter in substantially the form attached as Exhibit L to the Pooling Agreement, which investment letter
shall not be an expense of the Company, the Master Servicer, the Trust or the Trustee and (ii) in the event that such a transfer is
not made pursuant to Rule 144A under the Securities Act, the Trustee may require an Opinion of Counsel satisfactory to the Trustee
that such transfer may be made without such registration or qualification, which Opinion of Counsel shall not be an expense of the
Company, the Master Servicer, the Trust or the Trustee. Neither the Company nor the Trust will register the Certificate under the
Securities Act, qualify the Certificate under any state securities law or provide registration rights to any purchaser. Any Holder
desiring to effect such transfer shall, and does hereby agree to, indemnify the Trust, the Trustee, the Company and the Master
Servicer against any liability that may result if the transfer is not so exempt or is not made in accordance with such federal and
state laws.]


The Certificates are issuable only as registered Certificates without
coupons in Authorized Denominations specified in the Pooling Agreement. As provided in the Pooling Agreement and subject to certain
limitations therein set forth, Certificates are exchangeable for new Certificates of Authorized Denominations of like Certificate
Principal Balance or Percentage Interest, as applicable, as requested by the Holder surrendering the same.


A reasonable service charge may be made for any such registration of
transfer or exchange, and the Trustee may require payment of a sum sufficient to cover any tax or other governmental charge payable
in connection therewith.


The Company, the Trustee and the Certificate Registrar and any agent
of the Company, the Trustee or the Certificate Registrar may treat the Person in whose name this Certificate is registered as the
owner hereof for all purposes, and neither the Company, the Trustee, the Certificate Registrar nor any such agent shall be affected
by notice to the contrary.


The obligations created by the Pooling Agreement and the Trust created
thereby shall terminate upon (i) the later of the maturity or other liquidation (including purchase by the Master Servicer) of the
last Mortgage Loan remaining in the Trust or the disposition of all property acquired upon foreclosure or deed in lieu of
foreclosure of any Mortgage Loan, and (ii) the payment to Certificateholders of all amounts held by the Trustee and required to be
paid to them pursuant to the Pooling Agreement. In the event that the Company or the Master Servicer purchases any Mortgage Loan
pursuant to the Pooling Agreement, the Pooling Agreement generally requires that the Trustee distribute to the Certificateholders
in the aggregate an amount equal to 100% of the unpaid Principal Balance of such Mortgage Loan, plus unpaid accrued interest
thereon at the applicable Pass-Through Rate to the last day of the month in which such purchase occurs. The Pooling Agreement
permits, but does not require, the Master Servicer to purchase from the Trust all Mortgage Loans at the time subject thereto and
all property acquired in respect of any Mortgage Loan upon payment to the Certificateholders of the amounts specified in the
Pooling Agreement. The exercise of such right will effect early retirement of the Certificates, the Master Servicer’s right
to purchase being subject to the aggregate Principal Balance of the Mortgage Loans at the time of purchase being less than the
Clean-Up Call Percentage of the aggregate Principal Balance of the Mortgage Loans as of the Cut-Off Date.







ASSIGNMENT


 


FOR VALUE RECEIVED the undersigned hereby sell(s) and assign(s) and transfer(s) unto


                                
                                                                                                                                                                                  


                                
                                                                                                                                                                                  


(Please print or typewrite name and address, including postal
zip code of assignee. Please insert social security or other identifying number of assignee.)


the within WaMu
Mortgage Pass-Through Certificate and hereby irrevocably constitutes and appoints


                                
                                                                                                                                                                                  


Attorney to transfer said Certificate on the
Certificate Register, with full power of substitution in the premises.


Dated:
                        
           
                                                                                                           


Signature Guaranteed



                                                                                                            


 NOTICE:    The signature to this assignment must correspond with
the name as written upon the face of the within instrument in every particular, without alteration or enlargement or any change
whatever.  This Certificate does not represent an obligation of or an interest in Washington Mutual Mortgage Securities Corp.
or any of its affiliates.  Neither this Certificate nor the underlying Mortgage Loans are guaranteed by any agency or
instrumentality of the United States.









             Exhibit H-2






FORM OF ADDITIONAL MATTER INCORPORATED INTO


THE FORM OF THE CLASS Y
CERTIFICATES


This Certificate does not represent an
obligation of or interest in Washington Mutual Mortgage Securities Corp. or any of its affiliates. Neither this Certificate nor the
underlying Mortgage Loans are guaranteed by any agency or instrumentality of the United States.


This certifies that the above-named
Registered Owner is the registered owner of certain interests in a Yield Maintenance Agreement. To the extent not defined herein,
the capitalized terms used herein have the meanings assigned in the Pooling Agreement. Nothing herein shall be deemed inconsistent
with such meanings, and in the event of any conflict between the Pooling Agreement and the terms of this Certificate, the Pooling
Agreement shall control. This Certificate is issued under and is subject to the terms, provisions and conditions of the Pooling
Agreement, to which Pooling Agreement the Holder of this Certificate, by virtue of the acceptance hereof, assents and by which such
Holder is bound.


Distributions will be made, pursuant to
the Pooling Agreement, on the 25th day of each month or, if such 25th day is not a Business Day, the Business Day immediately
following (the “Distribution Date”), commencing on the first Distribution Date specified above, to the Person in whose
name this Certificate is registered at the close of business on the last day (or if such last day is not a Business Day, the
Business Day immediately preceding such last day) of the month immediately preceding the month of such distribution (the
“Record Date”), to the extent of such Certificateholder's rights under the Yield Maintenance Agreement then
distributable on the Certificates of this Class, as specified in Section 4.04 of the Pooling Agreement.


Distributions on this Certificate will
be made by the Trustee by wire transfer or check mailed to the address of the Person entitled thereto, as such name and address
shall appear on the Certificate Register. Notwithstanding the above, the final distribution on this Certificate will be made after
due notice by the Trustee of the pendency of such distribution and only upon presentation and surrender of this Certificate to the
Certificate Registrar.


Reference is hereby made to the further
provisions of this Certificate set forth below, which further provisions shall for all purposes have the same effect as if set
forth at this place.


Unless the certificate of
authentication hereon has been executed by or on behalf of the Trustee, by manual signature, this Certificate shall not be entitled
to any benefit under the Pooling Agreement or be valid for any purpose.







IN WITNESS WHEREOF, the Trust has
caused this Certificate to be duly executed.


WaMu MORTGAGE PASS-THROUGH
CERTIFICATES SERIES 2005-AR1 TRUST


 


By:    DEUTSCHE BANK NATIONAL TRUST COMPANY, as Trustee


 


By:
                                                                          


 


 


(TRUSTEE'S CERTIFICATE
OF AUTHENTICATION)


This is one of the Certificates
referred to in the within-mentioned Pooling Agreement.


DEUTSCHE BANK
NATIONAL TRUST COMPANY,


as Trustee


 


By:
                                                     


Dated:
                                                


 







WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.


WaMu MORTGAGE
PASS-THROUGH CERTIFICATE


This Certificate is one of a duly authorized issue of Certificates
designated as WaMu Mortgage Pass-Through Certificates of the Series and Class specified hereon (herein called the
“Certificates”) and representing certain interests in a Yield Maintenance Agreement, together with certain rights
specified in the Pooling Agreement.


The Certificates do not represent an obligation of, or an interest in,
the Company or any of its affiliates and are not insured or guaranteed by any governmental agency. The Certificates are limited in
right of payment pursuant to a Yield Maintenance Agreement, all as more specifically set forth herein and in the Pooling
Agreement.


As provided in the Pooling Agreement, withdrawals from the Certificate
Account may be made from time to time for purposes other than distributions to Certificateholders, such purposes including
reimbursement to the Master Servicer of advances made, or certain expenses incurred, by it.


The Pooling Agreement permits, with certain exceptions therein
provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of the
Certificateholders under the Pooling Agreement at any time by the Company, the Master Servicer and the Trustee with the consent of
the Holders of the Certificates evidencing Percentage Interests aggregating not less than 66% of REMIC II. Any such consent by the
Holder of this Certificate shall be conclusive and binding on such Holder and upon all future Holders of this Certificate and of
any Certificate issued upon the transfer hereof or in exchange herefor or in lieu hereof whether or not notation of such consent is
made upon this Certificate. The Pooling Agreement also permits the amendment thereof, in certain limited circumstances, without the
consent of the Holders of any of the Certificates.


As provided in the Pooling Agreement and subject to certain
limitations therein set forth, the transfer of this Certificate is registrable in the Certificate Register upon surrender of this
Certificate for registration of transfer at the offices of the Certificate Registrar or the office maintained by the Trustee in the
City and State of New York, duly endorsed by, or accompanied by an assignment in the form below or other written instrument of
transfer in form satisfactory to the Trustee or any Authenticating Agent duly executed by, the Holder hereof or such Holder's
attorney duly authorized in writing, and thereupon one or more new Certificates of Authorized Denominations evidencing the same
Percentage Interest set forth hereinabove will be issued to the designated transferee or transferees.


The Certificates are issuable only as registered Certificates without
coupons in Authorized Denominations specified in the Pooling Agreement. As provided in the Pooling Agreement and subject to certain
limitations therein set forth, Certificates are exchangeable for new Certificates of Authorized Denominations of like Certificate
Principal Balance or Percentage Interest, as applicable, as requested by the Holder surrendering the same.


A reasonable service charge may be made for any such registration of
transfer or exchange, and the Trustee may require payment of a sum sufficient to cover any tax or other governmental charge payable
in connection therewith.


The Company, the Trustee and the Certificate Registrar and any agent
of the Company, the Trustee or the Certificate Registrar may treat the Person in whose name this Certificate is registered as the
owner hereof for all purposes, and neither the Company, the Trustee, the Certificate Registrar nor any such agent shall be affected
by notice to the contrary.


The obligations created by the Pooling Agreement and the Trust created
thereby shall terminate upon (i) the later of the maturity or other liquidation (including purchase by the Master Servicer) of the
last Mortgage Loan remaining in the Trust or the disposition of all property acquired upon foreclosure or deed in lieu of
foreclosure of any Mortgage Loan, and (ii) the payment to Certificateholders of all amounts held by the Trustee and required to be
paid to them pursuant to the Pooling Agreement. In the event that the Company or the Master Servicer purchases any Mortgage Loan
pursuant to the Pooling Agreement, the Pooling Agreement generally requires that the Trustee distribute to the Certificateholders
in the aggregate an amount equal to 100% of the unpaid Principal Balance of such Mortgage Loan, plus unpaid accrued interest
thereon at the applicable Pass-Through Rate to the last day of the month in which such purchase occurs. The Pooling Agreement
permits, but does not require, the Master Servicer to purchase from the Trust all Mortgage Loans at the time subject thereto and
all property acquired in respect of any Mortgage Loan upon payment to the Certificateholders of the amounts specified in the
Pooling Agreement. The exercise of such right will effect early retirement of the Certificates, the Master Servicer’s right
to purchase being subject to the aggregate Principal Balance of the Mortgage Loans at the time of purchase being less than the
Clean-Up Call Percentage of the aggregate Principal Balance of the Mortgage Loans as of the Cut-Off Date.







 


ASSIGNMENT


 


FOR VALUE RECEIVED the undersigned hereby sell(s) and assign(s) and transfer(s) unto


                                
                                                                                                                                                                                  


                                
                                                                                                                                                                                  


(Please print or typewrite name and address, including postal
zip code of assignee. Please insert social security or other identifying number of assignee.)


the within WaMu
Mortgage Pass-Through Certificate and hereby irrevocably constitutes and appoints


                                
                                                                                                                                                                                  


Attorney to transfer said Certificate on the
Certificate Register, with full power of substitution in the premises.


Dated:
                        
           
                                                                                                           


Signature Guaranteed



                                                                                                            


 NOTICE:    The signature to this assignment must correspond with
the name as written upon the face of the within instrument in every particular, without alteration or enlargement or any change
whatever.  This Certificate does not represent an obligation of or an interest in Washington Mutual Mortgage Securities Corp.
or any of its affiliates.  Neither this Certificate nor the underlying Mortgage Loans are guaranteed by any agency or
instrumentality of the United States.






 



               Exhibit I






TRANSFEROR
CERTIFICATE FOR CLASS R CERTIFICATES


[Date]


Deutsche Bank
National Trust Company, as Trustee

1761 East St. Andrew Place

Santa Ana, CA 92705

Attn: Trust Administration WA05A1

 


Re:
     Washington Mutual Mortgage Securities Corp. WaMu Mortgage Pass-Through

Certificates, Series 2005-AR1, Class R


Ladies and Gentlemen:


This letter is delivered to you in
connection with the sale from
                                        
 (the “Seller”) to           
                                   
(the “Purchaser”) of $____________________ initial Certificate Principal Balance of WaMu Mortgage Pass-Through
Certificates, Series 2005-AR1, Class R (the “Certificate”), pursuant to Section 5.01 of the Pooling and Servicing
Agreement (the “Pooling Agreement”), dated as of January 1, 2005 among Washington Mutual Mortgage Securities Corp., as
depositor and master servicer (the “Company”), Deutsche Bank National Trust Company, as trustee (the
“Trustee”), and Deutsche Bank Trust Company Delaware, as Delaware trustee. All terms used herein and not otherwise
defined shall have the meanings set forth in the Pooling Agreement. The Seller hereby certifies, represents and warrants to, and
covenants with, the Company, the Trustee and the Trust that:


1.         No purpose of the Seller relating to the sale of the Certificate by the
Seller to the Purchaser is or will be to enable the Seller to impede the assessment or collection of tax.


2.         The Seller understands that the Purchaser has delivered to the Trustee
and the Company a transferee affidavit and agreement in the form attached to the Pooling Agreement as Exhibit J. The Seller does
not know or believe that any representation contained therein is false.


3.         The Seller has no actual knowledge that the proposed Transferee is not a
Permitted Transferee.


4.         The Seller has no actual knowledge that the Purchaser would be unwilling
or unable to pay taxes due on its share of the taxable income attributable to the Certificates.


5.         The Seller has conducted a reasonable investigation of the financial
condition of the Purchaser and, as a result of the investigation, found that the Purchaser has historically paid its debts as they
came due, and found no significant evidence to indicate that the Purchaser will not continue to pay its debts as they come due in
the future.


6.         The Purchaser has represented to the Seller that, if the Certificates
constitute a noneconomic residual interest, it (i) understands that as holder of a noneconomic residual interest it may incur tax
liabilities in excess of any cash flows generated by the interest, and (ii) intends to pay taxes associated with its holding of the
Certificates as they become due.



Very truly yours,



 



[Seller]



 



By:
                                                                             



      Name:
                                                                  



      Title:
                                                                     









Exhibit J






TRANSFEREE AFFIDAVIT
AND AGREEMENT FOR CLASS R CERTIFICATES


 


STATE
OF                  )


                                     
)   ss:


COUNTY
OF               )


 


[NAME OF OFFICER], being first duly
sworn, deposes and says:


1.         That he is [Title of Officer] of [Name of Owner] (record or beneficial
owner of the Class R Certificate (the “Owner”)), a [savings institution] [corporation] duly organized and existing
under the laws of [the State of
                  ] [the United
States], on behalf of which he makes this affidavit and agreement.


2.         That the Owner (i) is not and will not be a “disqualified
organization” as of [date of transfer] within the meaning of Section 860E(e)(5) of the Internal Revenue Code of 1986, as
amended (the “Code”) and will endeavor to remain other than a disqualified organization for so long as it retains its
ownership interest in the Class R Certificates, and (ii) is acquiring the Class R Certificates for its own account or for the
account of another Owner from which it has received an affidavit and agreement in substantially the same form as this affidavit and
agreement. (For this purpose, a disqualified organization” means the United States, any state or political subdivision
thereof, or any agency or instrumentality of any of the foregoing (other than an instrumentality all of the activities of which are
subject to tax and, except for the Federal Home Loan Mortgage Corporation, a majority of whose board of directors is not selected
by any such governmental entity), or any foreign government or international organization, or any agency or instrumentality of such
foreign government or organization, any rural electric or telephone cooperative, or any organization (other than certain farmers'
cooperatives) that is generally exempt from federal income tax unless such organization is subject to the tax on unrelated business
taxable income).


3.         That the Owner is aware (i) of the tax that would be imposed on transfers
of the Class R Certificates after March 31, 1988; (ii) that such tax would be on the transferor, or, if such transfer is through an
agent (which person includes a broker, nominee or middle-man) for a disqualified organization, on the agent; (iii) that the person
otherwise liable for the tax shall be relieved of liability for the tax if the transferee furnishes to such person an affidavit
that the transferee is not a disqualified organization and, at the time of transfer, such person does not have actual knowledge
that the affidavit is false; and (iv) that the Class R Certificates may be a “noneconomic residual interest” within the
meaning of Treasury regulations promulgated pursuant to the Code and that the transferor of a noneconomic residual interest will
remain liable for any taxes due with respect to the income on such residual interest, if a significant purpose of the transfer was
to enable the transferor to impede the assessment or collection of tax.


4.         That the Owner is aware of the tax imposed on a “pass-through
entity” holding the Class R Certificates if at any time during the taxable year of the pass-through entity a disqualified
organization is the record holder of an interest in such entity. (For this purpose, a “pass through entity” includes a
regulated investment company, a real estate investment trust or common trust fund, a partnership, trust or estate, and certain
cooperatives.)


5.         That the Owner is aware that the Trustee will not register the Transfer
of the Class R Certificates unless the transferee, or the transferees' agent, delivers to it an affidavit and agreement, among
other things, in substantially the same form as this affidavit and agreement. The Owner expressly agrees that it will not
consummate any such transfer if it knows or believes that any of the representations contained in such affidavit and agreement are
false.


6.         That the Owner has reviewed the restrictions set forth on the face of the
Class R Certificates and the provisions of Section 5.01 of the Pooling Agreement under which the Class R Certificates were issued
(in particular, clauses (iii)(A) and (iii)(B) of Section 5.01(c) which authorize the Trustee to deliver payments to a person other
than the Owner and negotiate a mandatory sale by the Trustee in the event the Owner holds such Certificates in violation of Section
5.01). The Owner expressly agrees to be bound by and to comply with such restrictions and provisions.


7.         That the Owner consents to any additional restrictions or arrangements
that shall be deemed necessary upon advice of counsel to constitute a reasonable arrangement to ensure that the Class R
Certificates will only be owned, directly or indirectly, by an Owner that is not a disqualified organization.


8.         The Owner's Taxpayer Identification Number is
                              
..


9.         That no purpose of the Owner relating to the purchase of the Class R
Certificates by the Owner is or will be to enable the transferor to impede the assessment or collection of tax, and that in making
this representation, the Owner warrants that the Owner is familiar with Treasury Regulation 1.860E-1(c) and with the preamble to
the adoption of amendments to that regulation as of July 19, 2002, attached hereto as Exhibit 1.


10.        That the Owner anticipates that it will, so long as it holds the Class R
Certificates, have sufficient assets to pay any taxes owed by the holder of such Certificates, and hereby represents to and for the
benefit of the person from whom it acquired the Class R Certificates that the Owner intends to pay taxes associated with holding
such Certificates as they become due, fully understanding that it may incur tax liabilities in excess of any cash flows generated
by the Class R Certificates. That the Owner has provided financial statements or other financial information requested by the
transferor in connection with the transfer of the Class R Certificates to permit the transferor to assess the financial capability
of the Owner to pay such taxes.


11.        That the Owner has no present knowledge or expectation that it will be unable
to pay any United States taxes owed by it so long as any of the Class R Certificates remain outstanding.


12.        That the Owner has no present knowledge or expectation that it will become
insolvent or subject to a bankruptcy proceeding for so long as any of the Class R Certificates remain outstanding.


13.        That the Owner is familiar with Treasury Regulation 1.860E-1(c) and with the
preamble to the adoption of amendments to that regulation as of July 19, 2002, attached hereto as Exhibit 1, and that no purpose of
the Owner relating to any sale of the Class R Certificates by the Owner will be to impede the assessment or collection of
tax.


14.        The Owner is a citizen or resident of the United States, a corporation,
partnership or other entity treated as a partnership or corporation for U.S. federal income tax purposes created or organized in,
or under the laws of, the United States or any state thereof or the District of Columbia, or an estate or trust whose income from
sources without the United States is includible in gross income for United States federal income tax purposes regardless of its
connection with the conduct of a trade or business within the United States.


15.        The Owner hereby agrees that it will not cause income from the Class R
Certificates to be attributable to a foreign permanent establishment or fixed base (within the meaning of an applicable income tax
treaty) of the Owner or another United States taxpayer.


16.        The Owner hereby agrees to cooperate with the Company and to take any action
required of it by the Code or Treasury regulations thereunder (whether now or hereafter promulgated) in order to create or maintain
the REMIC status of REMIC I and REMIC II (the “REMICs”).


17.        The Owner hereby agrees that it will not take any action that could endanger
the REMIC status of the REMICs or result in the imposition of tax on the REMICs unless counsel for, or acceptable to, the Company
has provided an opinion that such action will not result in the loss of such REMIC status or the imposition of such tax, as
applicable.


18.        The Owner as transferee of the Class R Certificates has represented to the
transferor that, if the Class R Certificates constitute a noneconomic residual interest, the Owner (i) understands that as holder
of a noneconomic residual interest it may incur tax liabilities in excess of any cash flows generated by the interest, and (ii)
intends to pay taxes associated with its holding of the Class R Certificates as they become due.


           
19.        That the Owner satisfies the condition in the paragraph marked below [mark one
paragraph only]:


___      The
Owner is not an employee benefit or other plan subject to the prohibited transaction provisions of the Employee Retirement Income
Security Act of 1974, as amended, or Section 4975 of the Internal Revenue Code of 1986, as amended (a “Plan”), or any
other person (including an investment manager, a named fiduciary or a trustee of any Plan) acting, directly or indirectly, on
behalf of, or purchasing the Class R Certificates with “plan assets” of, any Plan within the meaning of the Department
of Labor (“DOL”) regulation at 29 C.F.R. Section 2510.3-101.


___      The Owner has delivered a Benefit Plan Opinion (as defined in Section 1.01 of the Pooling
Agreement under which the Class R Certificates were issued).


IN WITNESS WHEREOF, the Owner has
caused this instrument to be executed on its behalf, pursuant to the authority of its Board of Directors, by its [Title of Officer]
and its corporate seal to be hereunto attached, attested by its [Assistant] Secretary, this
          day of          ,
20 __ .


[Name of Owner]



By:                                                      



                  [Name of
Officer]


                   [Title of
Officer]


[Corporate Seal]


ATTEST:


 


 


[Assistant] Secretary


Personally appeared before me the
above-named [Name of Officer], known or proved to me to be the same person who executed the foregoing instrument and to be the
[Title of Officer] of the Owner, and Acknowledged to me that he executed the same as his free act and deed and the free act and
deed of the Owner.


Subscribed and sworn before me this ___
day of __________________, 20__.


 


 



NOTARY PUBLIC



 



COUNTY OF



STATE OF



My Commission expires the     day



of
                     ,
20     












        Exhibit 1 to Transferee Affidavit


 


DEPARTMENT OF THE TREASURY

Internal Revenue Service

26 CFR Parts 1 and 602

[TD 9004]

RIN 1545-AW98


 


Real Estate Mortgage Investment Conduits


AGENCY: Internal Revenue Service (IRS), Treasury.


ACTION: Final regulations.


-----------------------------------------------------------------------


SUMMARY: This document contains final regulations relating to safe harbor transfers of noneconomic residual interests in
real estate mortgage investment conduits (REMICs). The final regulations provide additional limitations on the circumstances under
which transferors may claim safe harbor treatment.


DATES:           Effective Date: These regulations are effective July 19,
2002.


Applicability
Date: For dates of applicability, see Sec. 1.860E-


(1)(c)(10).


FOR FURTHER INFORMATION CONTACT: Courtney Shepardson at (202) 622-3940 (not a toll-free number).


SUPPLEMENTARY INFORMATION:


Paperwork Reduction Act


The collection of information in this final rule has been reviewed and, pending receipt and evaluation of public comments,
approved by the Office of Management and Budget (OMB) under 44 U.S.C. 3507 and assigned control number 1545-1675.  The
collection of information in this regulation is in Sec. 1.860E-1(c)(5)(ii). This information is required to enable the IRS to
verify that a taxpayer is complying with the conditions of this regulation. The collection of information is mandatory and is
required. Otherwise, the taxpayer will not receive the benefit of safe harbor treatment as provided in the regulation. The likely
respondents are businesses and other for-profit institutions.


Comments on the collection of information should be sent to the Office of Management and Budget, Attn: Desk Officer for the
Department of the Treasury, Office of Information and Regulatory Affairs, Washington, DC, 20503, with copies to the Internal
Revenue Service, Attn: IRS Reports Clearance Officer, W:CAR:MP:FP:S, Washington, DC 20224. Comments on the collection of
information should be received by September 17, 2002. Comments are specifically requested concerning: 


 


Whether the
collection of information is necessary for the proper performance of the functions of the Internal Revenue Service, including
whether the information will have practical utility; 


 


The accuracy of the
estimated burden associated with the collection of information (see below);


 


How the quality,
utility, and clarity of the information to be collected may be enhanced;


 


How the burden of
complying with the collection of information may be minimized, including through the application of automated collection techniques
or other forms of information technology; and


 


Estimates of
capital or start-up costs and costs of operation, maintenance, and purchase of service to provide information.


An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it
displays a valid control number assigned by the Office of Management and Budget.   


The estimated total annual reporting burden is 470 hours, based on an estimated number of respondents of 470 and an
estimated average annual burden hours per respondent of one hour.


Books or records relating to a collection of information must be retained as long as their contents may become material in
the administration of any internal revenue law. Generally, tax returns and tax return information are confidential, as required by
26 U.S.C. 6103.


Background


This document contains final regulations regarding the proposed amendments to 26 CFR part 1 under section 860E of the
Internal Revenue Code (Code). The regulations provide the circumstances under which a transferor of a noneconomic REMIC residual
interest meeting the investigation and representation requirements may avail itself of the safe harbor by satisfying either the
formula test or the asset test.


Final regulations governing REMICs, issued in 1992, contain rules governing the transfer of noneconomic REMIC residual
interests. In general, a transfer of a noneconomic residual interest is disregarded for all tax purposes if a significant purpose
of the transfer is to enable the transferor to impede the assessment or collection of tax. A purpose to impede the assessment or
collection of tax (a wrongful purpose) exists if the transferor, at the time of the transfer, either knew or should have known that
the transferee would be unwilling or unable to pay taxes due on its share of the REMIC's taxable income.


Under a safe harbor, the transferor of a REMIC noneconomic residual interest is presumed not to have a wrongful purpose if
two requirements are satisfied: (1) the transferor conducts a reasonable investigation of the transferee's financial condition (the
investigation requirement); and (2) the transferor secures a representation from the transferee to the effect that the transferee
understands the tax obligations associated with holding a residual interest and intends to pay those taxes (the representation
requirement).


The IRS and Treasury have been concerned that some transferors of noneconomic residual interests claim they satisfy the safe
harbor even in situations where the economics of the transfer clearly indicate the transferee is unwilling or unable to pay the tax
associated with holding the interest. For this reason, on February 7, 2000, the IRS published in the Federal Register (65 FR 5807)
a notice of proposed rulemaking (REG-100276-97; REG-122450-98) designed to clarify the safe harbor by adding the ``formula test,''
an economic test. The proposed regulation provides that the safe harbor is unavailable unless the present value of the anticipated
tax liabilities associated with holding the residual interest does not exceed the sum of: (1) The present value of any
consideration given to the transferee to acquire the interest; (2) the present value of the expected future distributions on the
interest; and (3) the present value of the anticipated tax savings associated with holding the interest as the REMIC generates
losses.


The notice of proposed rulemaking also contained rules for FASITs. Section 1.860H-6(g) of the proposed regulations provides
requirements for transfers of FASIT ownership interests and adopts a safe harbor by reference to the safe harbor provisions of the
REMIC regulations.   


In January 2001, the IRS published Rev. Proc. 2001-12 (2001-3 I.R.B. 335) to set forth an alternative safe harbor that
taxpayers could use while the IRS and the Treasury considered comments on the proposed regulations. Under the alternative safe
harbor, if a transferor meets the investigation requirement and the representation requirement but the transfer fails to meet the
formula test, the transferor may invoke the safe harbor if the transferee meets a two-prong test (the asset test). A transferee
generally meets the first prong of this test if, at the time of the transfer, and in each of the two years preceding the year of
transfer, the transferee's gross assets exceed $100 million and its net assets exceed $10 million. A transferee generally meets the
second prong of this test if it is a domestic, taxable corporation and agrees in writing not to transfer the interest to any person
other than another domestic, taxable corporation that also satisfies the requirements of the asset test. A transferor cannot rely
on the asset test if the transferor knows, or has reason to know, that the transferee will not comply with its written agreement to
limit the restrictions on subsequent transfers of the residual interest.


Rev. Proc. 2001-12 provides that the asset test fails to be satisfied in the case of a transfer or assignment of a
noneconomic residual interest to a foreign branch of an otherwise eligible transferee. If such a transfer or assignment were
permitted, a corporate taxpayer might seek to claim that the provisions of an applicable income tax treaty would resource excess
inclusion income as foreign source income, and that, as a consequence, any U.S. tax liability attributable to the excess inclusion
income could be offset by foreign tax credits. Such a claim would impede the assessment or collection of U.S. tax on excess
inclusion income, contrary to the congressional purpose of assuring that such income will be taxable in all events. See, e.g.,
sections 860E(a)(1), (b), (e) and 860G(b) of the Code.


The Treasury and the IRS have learned that certain taxpayers transferring noneconomic residual interests to foreign branches
have attempted to rely on the formula test to obtain safe harbor treatment in an effort to impede the assessment or collection of
U.S. tax on excess inclusion income. Accordingly, the final regulations provide that if a noneconomic residual interest is
transferred to a foreign permanent establishment or fixed base of a U.S. taxpayer, the transfer is not eligible for safe harbor
treatment under either the asset test or the formula test. The final regulations also require a transferee to represent that it
will not cause income from the noneconomic residual interest to be attributable to a foreign permanent establishment or fixed
base.


Section 1.860E-1(c)(8) provides computational rules that a taxpayer may use to qualify for safe harbor status under the
formula test. Section 1.860E-1(c)(8)(i) provides that the transferee is presumed to pay tax at a rate equal to the highest rate of
tax specified in section 11(b). Some commentators were concerned that this presumed rate of taxation was too high because it does
not take into consideration taxpayers subject to the alternative minimum tax rate. In light of the comments received, this
provision has been amended in the final regulations to allow certain transferees that compute their taxable income using the
alternative minimum tax rate to use the alternative minimum tax rate applicable to corporations.


Additionally, Sec. 1.860E-1(c)(8)(iii) provides that the present values in the formula test are to be computed using a
discount rate equal to the applicable Federal short-term rate prescribed by section 1274(d). This is a change from the proposed
regulation and Rev. Proc. 2001-12. In those publications the provision stated that “present values are computed using a
discount rate equal to the applicable Federal rate prescribed in section 1274(d) compounded semiannually” and that “[a]
lower discount rate may be used if the transferee can demonstrate that it regularly borrows, in the course of its trade or
business, substantial funds at such lower rate from an unrelated third party.”  The IRS and the Treasury Department have
learned that, based on this provision, certain taxpayers have been attempting to use unrealistically low or zero interest rates to
satisfy the formula test, frustrating the intent of the test. Furthermore, the Treasury Department and the IRS believe that a rule
allowing for a rate other than a rate based on an objective index would add unnecessary complexity to the safe harbor. As a result,
the rule in the proposed regulations that permits a transferee to use a lower discount rate, if the transferee can demonstrate that
it regularly borrows substantial funds at such lower rate, is not included in the final regulations; and the Federal short-term
rate has been substituted for the applicable Federal rate. To simplify taxpayers' computations, the final regulations allow use of
any of the published short-term rates, provided that the present values are computed with a corresponding period of compounding.
With the exception of the provisions relating to transfers to foreign branches, these changes generally have the proposed
applicability date of February 4, 2000, but taxpayers may choose to apply the interest rate formula set forth in the proposed
regulation and Rev. Proc. 2001-12 for transfers occurring before August 19, 2002.


It is anticipated that when final regulations are adopted with respect to FASITs, Sec. 1.860H-6(g) of the proposed
regulations will be adopted in substantially its present form, with the result that the final regulations contained in this
document will also govern transfers of FASIT ownership interests with substantially the same applicability date as is contained in
this document.


Effect on Other Documents


Rev. Proc. 2001-12 (2001-3 I.R.B. 335) is obsolete for transfers of noneconomic residual interests in REMICs occurring on or
after August 19, 2002.


Special Analyses


It is hereby certified that these regulations will not have a significant economic impact on a substantial number of small
entities. This certification is based on the fact that it is unlikely that a substantial number of small entities will hold REMIC
residual interests. Therefore, a Regulatory Flexibility Analysis under the Regulatory Flexibility Act (5 U.S.C. chapter 6) is not
required. It has been determined that this Treasury decision is not a significant regulatory action as defined in Executive Order
12866. Therefore, a regulatory assessment is not required. It also has been determined that sections 553(b) and 553(d) of the
Administrative Procedure Act (5 U.S.C. chapter 5) do not apply to these regulations.


Drafting Information


The principal author of these regulations is Courtney Shepardson. However, other personnel from the IRS and Treasury
Department participated in their development.


List of Subjects


26 CFR Part 1


Income taxes, Reporting and record keeping requirements.


26 CFR Part 602


Reporting and record keeping requirements.


Adoption of Amendments to the Regulations


Accordingly, 26 CFR parts 1 and 602 are amended as follows:


PART 1--INCOME TAXES

 


Paragraph 1. The
authority citation for part 1 continues to read in part as follows 


    Authority: 26 U.S.C. 7805 * * *







Exhibit K


[Reserved]


 


 












                 Exhibit L






[FORM OF RULE 144A
INVESTMENT REPRESENTATION]


Description of Rule
144A Securities, including numbers:


                                                  


                                                  


                                                  


                                                  


 


The undersigned  seller, as
registered holder (the “Seller”), intends to transfer the Rule 144A Securities described above to the undersigned buyer
(the “Buyer”).


1.         In connection with such transfer and in accordance with the agreements
pursuant to which the Rule 144A Securities were issued, the Seller hereby certifies the following facts: Neither the Seller nor
anyone acting on its behalf has offered, transferred, pledged, sold or otherwise disposed of the Rule 144A Securities, any interest
in the Rule 144A Securities or any other similar security to, or solicited any offer to buy or accept a transfer, pledge or other
disposition of the Rule 144A Securities, any interest in the Rule 144A Securities or any other similar security from, or otherwise
approached or negotiated with respect to the Rule 144A Securities, any interest in the Rule 144A Securities or any other similar
security with, any person in any manner, or made any general solicitation by means of general advertising or in any other manner,
or taken any other action, that would constitute a distribution of the Rule 144A Securities under the Securities Act of 1933, as
amended (the “1933 Act”), or that would render the disposition of the Rule 144A Securities a violation of Section 5 of
the 1933 Act or require registration pursuant thereto, and that the Seller has not offered the Rule 144A Securities to any person
other than the Buyer or another “qualified institutional buyer” as defined in Rule 144A under the 1933 Act.


2.         The Buyer warrants and represents to, and covenants with, the Seller, the
Trustee, the Trust and the Master Servicer (as defined in Section 1.01 of the Pooling and Servicing Agreement (the
“Agreement”) dated as of January 1, 2005 among Washington Mutual Mortgage Securities Corp., as Depositor and Master
Servicer, Deutsche Bank National Trust Company, as Trustee, and Deutsche Bank Trust Company Delaware, as Delaware Trustee) pursuant
to Section 5.01(f) of the Agreement, as follows:


a.         The Buyer understands that the Rule 144A Securities have not been
registered under the 1933 Act or the securities laws of any state.


b.         The Buyer considers itself a substantial, sophisticated institutional
investor having such knowledge and experience in financial and business matters that it is capable of evaluating the merits and
risks of investment in the Rule 144A Securities.


c.         The Buyer has received and reviewed the Private Placement Memorandum
dated January 18, 2005 relating to the Rule 144A Securities and has been furnished with all information regarding the Rule 144A
Securities that it has requested from the Seller, the Trustee, the Company or the Master Servicer.


d.         Neither the Buyer nor anyone acting on its behalf has offered,
transferred, pledged, sold or otherwise disposed of the Rule 144A Securities, any interest in the Rule 144A Securities or any other
similar security to, or solicited any offer to buy or accept a transfer, pledge or other disposition of the Rule 144A Securities,
any interest in the Rule 144A Securities or any other similar security from, or otherwise approached or negotiated with respect to
the Rule 144A Securities, any interest in the Rule 144A Securities or any other similar security with, any person in any manner, or
made any general solicitation by means of general advertising or in any other manner, or taken any other action, that would
constitute a distribution of the Rule 144A Securities under the 1933 Act or that would render the disposition of the Rule 144A
Securities a violation of Section 5 of the 1933 Act or require registration pursuant thereto, nor will it act, nor has it
authorized or will it authorize any person to act, in such manner with respect to the Rule 144A Securities.


e.         The Buyer is a “qualified institutional buyer” as that term
is defined in Rule 144A under the 1933 Act and has (1) completed either of the forms of certification to that effect attached
hereto as Annex 1 or Annex 2, or (2) obtained the waiver of the Company with respect to Annex 1 and Annex 2 pursuant to
Section 5.01(f) of the Agreement. The Buyer is aware that the sale to it is being made in reliance on Rule 144A. The Buyer is
acquiring the Rule 144A Securities for its own account or the accounts of other qualified institutional buyers, understands that
such Rule 144A Securities may be resold, pledged or transferred only (i) to a person reasonably believed to be a qualified
institutional buyer that purchases for its own account or for the account of a qualified institutional buyer to whom notice is
given that the resale, pledge or transfer is being made in reliance on Rule 144A, or (ii) pursuant to another exemption from
registration under the 1933 Act.


f.          The Buyer is not affiliated with (i) the Trustee or
(ii) any Rating Agency that rated the Rule 144A Securities.


g.         If applicable, the Buyer has complied, and will continue to comply, with
the guidelines established by Thrift Bulletin 13a issued April 23, 1998, by the Office of Regulatory Activities of the Federal Home
Loan Bank System.


3.         This document may be executed in one or more counterparts and by the
different parties hereto on separate counterparts, each of which, when so executed, shall be deemed to be an original; such
counterparts, together, shall constitute one and the same document.


IN WITNESS WHEREOF, each of the parties
has executed this document as of the date set forth below.


 


                                                                       
           
                                                                       


                    
Print Name of
Seller                                                    
Print Name of Buyer


By:
                                                                 
            By:
                                                                 



Name:                                                                         
Name:      



Title:
                                                                           
Title:


 


Taxpayer
Identification:
                              
            Taxpayer Identification:
                             


No.:
                                                                
            No.:
                                                                


Date:
                                                              
            Date:
                                                              


 












   Annex 1 to
Exhibit L


QUALIFIED
INSTITUTIONAL BUYER STATUS UNDER SEC RULE 144A


[For Buyers Other Than
Registered Investment Companies]


 


The undersigned hereby certifies as
follows in connection with the Rule 144A Investment Representation to which this Certification is attached:


1.         As indicated below, the undersigned is the President, Chief Financial
Officer, Senior Vice President or other executive officer of the Buyer.


2.         In connection with purchases by the Buyer, the Buyer is a
“qualified institutional buyer” as that term is defined in Rule 144A under the Securities Act of 1933 (“Rule
144A”) because (i) the Buyer owned and/or invested on a discretionary basis $______________________ (the Buyer must own
and/or invest on a discretionary basis at least $100,000,000 in securities unless the Buyer is a dealer, and, in that case, the
Buyer must own and/or invest on a discretionary basis at least $10,000,000 in securities) in securities (except for the excluded
securities referred to below) as of the end of the Buyer's most recent fiscal year (such amount being calculated in accordance with
Rule 144A) and (ii) the Buyer satisfies the criteria in the category marked below.


___     
Corporation, etc. The Buyer is a corporation (other than a bank, savings and loan association or similar institution),
Massachusetts or similar business trust, partnership, or charitable organization described in Section 501(c)(3) of the Internal
Revenue Code.


___     
Bank. The Buyer (a) is a national bank or banking institution organized under the laws of any State, territory or the
District of Columbia, the business of which is substantially confined to banking and is supervised by the State or territorial
banking commission or similar official or is a foreign bank or equivalent institution, and (b) has an audited net worth of at least
$25,000,000 as demonstrated in its latest annual financial statements, a copy of which is attached hereto.


___     
Savings and Loan. The Buyer (a) is a savings and loan association, building and loan association, cooperative bank,
homestead association or similar institution, which is supervised and examined by a State or Federal authority having supervision
over any such institutions or is a foreign savings and loan association or equivalent institution and (b) has an audited net worth
of at least $25,000,000 as demonstrated in its latest annual financial statements.


___     
Broker-Dealer. The Buyer is a dealer registered pursuant to Section 15 of the Securities Exchange Act of 1934.


___     
Insurance Company. The Buyer is an insurance company whose primary and predominant business activity is the writing of
insurance or the reinsuring of risks underwritten by insurance companies and which is subject to supervision by the insurance
commissioner or a similar official or agency of a State or territory or the District of Columbia.


___     
State or Local Plan. The Buyer is a plan established and maintained by a State, its political subdivisions, or any agency or
instrumentality of the State or its political subdivisions, for the benefit of its employees.


___     
ERISA Plan. The Buyer is an employee benefit plan within the meaning of Section 3(3) of the Employee Retirement Income
Security Act of 1974, as amended (“ERISA”) and is subject to the fiduciary responsibility provisions of
ERISA.


___     
Investment Adviser. The Buyer is an investment adviser registered under the Investment Advisers Act of 1940.


___     
SBIC. The Buyer is a Small Business Investment Company licensed by the U.S. Small Business Administration under Section
301(c) or (d) of the Small Business Investment Act of 1958.


___     
Business Development Company. The Buyer is a business development company as defined in Section 202(a)(22) of the Investment
Advisers Act of 1940.


___     
Trust Fund. The Buyer is a trust fund whose trustee is a bank or trust company and whose participants are exclusively (a)
plans established and maintained by a State, its political subdivisions, or any agency or instrumentality of the State or its
political subdivisions, for the benefit of its employees, or (b) employee benefit plans within the meaning of Title I of the
Employee Retirement Income Security Act of 1974, but is not a trust fund that includes as participants individual retirement
accounts or H.R. 10 plans.


3.         The term “securities” as used herein does not
include (i) securities of issuers that are affiliated with the Buyer, (ii) securities that are part of an unsold
allotment to or subscription by the Buyer, if the Buyer is a dealer, (iii) bank deposit notes and certificates of deposit,
(iv) loan participations, (v) repurchase agreements, (vi) securities owned but subject to a repurchase agreement and
(vii) currency, interest rate and commodity swaps.


4.         For purposes of determining the aggregate amount of securities owned
and/or invested on a discretionary basis by the Buyer, the Buyer used the cost of such securities to the Buyer and did not include
any of the securities referred to in the preceding paragraph. Further, in determining such aggregate amount, the Buyer may have
included securities owned by subsidiaries of the  Buyer,  but only if such subsidiaries are consolidated with the Buyer
in its financial statements prepared in accordance with generally accepted accounting principles and if the investments of such
subsidiaries are managed under the Buyer's direction. However, such securities were not included if the Buyer is a majority-owned,
consolidated subsidiary of another enterprise and the Buyer is not itself a reporting company under the Securities Exchange Act of
1934.


5.         The Buyer acknowledges that it is familiar with Rule 144A and understands
that the seller to it and other parties related to the Certificates are relying and will continue to rely on the statements made
herein because one or more sales to the Buyer may be in reliance on Rule 144A.







                                   
           
            Will the Buyer be purchasing the Rule 144A

                         
   Yes                   
No                       
Securities only for the Buyer's own account?


6.         If the answer to the foregoing question is “no”, the Buyer
agrees that, in connection with any purchase of securities sold to the Buyer for the account of a third party (including any
separate account) in reliance on Rule 144A, the Buyer will only purchase for the account of a third party that at the time is
a “qualified institutional buyer” within the meaning of Rule 144A. In addition, the Buyer agrees that the Buyer
will not purchase securities for a third party unless the Buyer has obtained a current representation letter from such third party
or taken other appropriate steps contemplated by Rule 144A to conclude that such third party independently meets the
definition of “qualified institutional buyer” set forth in Rule 144A.


7.         The Buyer will notify each of the parties to which this certification is
made of any changes in the information and conclusions herein. Until such notice is given, the Buyer's purchase of Rule 144A
Securities will constitute a reaffirmation of this certification as of the date of such purchase.


 


            
                                                           


 Print Name of Buyer


By:
                                                                 


 Name:      

 Title:


Date:
                                                              


 







Annex 2 to Exhibit
L


QUALIFIED INSTITUTIONAL
BUYER STATUS UNDER SEC RULE 144A


[For Buyers That Are
Registered Investment Companies]


 


The undersigned hereby certifies as
follows in connection with the Rule 144A Investment Representation to which this Certification is attached:


1.         As indicated below, the undersigned is the President, Chief Financial
Officer or Senior Vice President of the Buyer or, if the Buyer is a “qualified institutional buyer” as that term is
defined in Rule 144A under the Securities Act of 1933 (“Rule 144A”) because Buyer is part of a Family of Investment
Companies (as defined below), is such an officer of the Adviser.


2.         In connection with purchases by Buyer, the Buyer is a “qualified
institutional buyer” as defined in SEC Rule 144A because (i) the Buyer is an investment company registered under the
Investment Company Act of 1940, and (ii) as marked below, the Buyer alone, or the Buyer's Family of Investment Companies, owned at
least $100,000,000 in securities (other than the excluded securities referred to below) as of the end of the Buyer's most recent
fiscal year. For purposes of determining the amount of securities owned by the Buyer or the Buyer's Family of Investment Companies,
the cost of such securities was used.


____    The Buyer owned
$___________________ in securities (other than the excluded securities referred to below) as of the end of the Buyer's most recent
fiscal year (such amount being calculated in accordance with Rule 144A).


____    The Buyer is
part of a Family of Investment Companies which owned in the aggregate $______________ in securities (other than the excluded
securities referred to below) as of the end of the Buyer's most recent fiscal year (such amount being calculated in accordance with
Rule 144A).


3.         The term “Family of Investment Companies” as used
herein means two or more registered investment companies (or series thereof) that have the same investment adviser or investment
advisers that are affiliated (by virtue of being majority owned subsidiaries of the same parent or because one investment adviser
is a majority owned subsidiary of the other).


4.         The term “securities” as used herein does not include
(i) securities of issuers that are affiliated with the Buyer or are part of the Buyer's Family of Investment Companies, (ii) bank
deposit notes and certificates of deposit, (iii) loan participations, (iv) repurchase agreements, (v) securities owned but subject
to a repurchase agreement and (vi) currency, interest rate and commodity swaps.


5.         The Buyer is familiar with Rule 144A and understands that each of the
parties to which this certification is made are relying and will continue to rely on the statements made herein because one or more
sales to the Buyer will be in reliance on Rule 144A. In addition, the Buyer will only purchase for the Buyer's own
account.


6.         The undersigned will notify each of the parties to which this
certification is made of any changes in the information and conclusions herein. Until such notice, the Buyer's purchase of Rule
144A Securities will constitute a reaffirmation of this certification by the undersigned as of the date of such
purchase.


 





_______________________________

Print Name of Buyer


By:_____________________________

Name:

Title:



Date:___________________________


 


IF AN ADVISER:


________________________________

Print Name of Buyer


By:______________________________

Name:

Title:



Date:_____________________________








 


 


(SEAL)












                Exhibit M




[Date]


[Company]


Re:       Pooling and Servicing Agreement dated as of January 1, 2005 by and among Washington
Mutual Mortgage Securities Corp., as Depositor and Master Servicer, Deutsche Bank National Trust Company, as Trustee, and Deutsche
Bank Trust Company Delaware, as Delaware Trustee, relating to Washington Mutual Mortgage Securities Corp. WaMu Mortgage
Pass-Through Certificates, Series 2005-AR1


Ladies and Gentlemen:


In accordance with Section 2.07 of the
above-captioned Pooling and Servicing Agreement, the undersigned, as [Trustee] [Initial Custodian], hereby certifies that, except
as noted on the attachment hereto, as to each Mortgage Loan listed in the Mortgage Loan Schedule (other than any Mortgage Loan paid
in full or listed on the attachment hereto) it has reviewed the documents delivered to it pursuant to Section 2.05 of the Pooling
and Servicing Agreement and has determined that (i) all documents required (in the case of instruments described in clauses
(X)(ii), (X)(iv) and (Y)(ix) of the definition of “Mortgage File,” known by it to be required) pursuant to the
definition of “Mortgage File” and Section 2.05 of the Pooling and Servicing Agreement to have been executed and
received as of the date hereof are in its possession and (ii) all such documents have been executed and relate to the Mortgage
Loans identified in the Mortgage Loan Schedule. The [Trustee] [Initial Custodian] has made no independent examination of such
documents beyond the review specifically required in the above referenced Pooling and Servicing Agreement and has relied upon the
purported genuineness and due execution of any such documents and upon the purported genuineness of any signature thereon. The
[Trustee] [Initial Custodian] makes no representations as to: (i) the validity, legality, enforceability or genuineness of any of
the documents contained in each Mortgage File or any of the Mortgage Loans identified on the Mortgage Loan Schedule, or (ii) the
collectability, insurability, effectiveness or suitability of any such Mortgage Loan.


Capitalized words and phrases used
herein shall have the respective meanings assigned to them in the above-captioned Pooling and Servicing Agreement.


 


                                                                                   
                                                                       



                                                                                   
as [Trustee] [Initial Custodian]


                                                                                   
By:
                                                                 



                                                                                   
Name:      



                                                                                   
Title:












                 Exhibit N


BENEFIT PLAN
AFFIDAVIT


Deutsche Bank
National Trust Company, as Trustee (the “Trustee”)

1761 East St. Andrew Place

Santa Ana, CA 92705

Attn: Trust Administration WA05A1


Washington Mutual Mortgage Securities Corp. (“Washington Mutual”)

75 North Fairway Drive

Vernon Hills, IL  60061


 


RE:       CLASS [B-4][B-5][B-6] CERTIFICATES (THE “PURCHASED
CERTIFICATES”)



ISSUED BY WaMu MORTGAGE PASS-THROUGH CERTIFICATES SERIES 2005-AR1


TRUST (THE
“TRUST”)


Under penalties of perjury, I,
_____________________, declare that, to the best of my knowledge and belief, the following representations are true, correct and
complete; and


1.         That I am the _______________ of __________________ (the
“Purchaser”), whose taxpayer identification number is  ___________, and on behalf of which I have the authority to
make this affidavit.


2.         That the Purchaser is acquiring a Purchased Certificate representing an
interest in the assets of the Trust.


3.         That the Purchaser satisfies the condition in the paragraph marked below
[mark one paragraph only]:


___      The
Purchaser is not an employee benefit plan or other plan subject to the prohibited transaction provisions of the Employee Retirement
Income Security Act of 1974, as amended, or Section 4975 of the Internal Revenue Code of 1986, as amended (a “Plan”),
or any other person (including an investment manager, a named fiduciary or a trustee of any Plan) acting, directly or indirectly,
on behalf of, or purchasing any of the Purchased Certificates with “plan assets” of, any Plan within the meaning of the
Department of Labor (“DOL”) regulation at 29 C.F.R. Section 2510.3-101.


___      The Purchaser is an insurance company, the source of funds to be used by it to acquire or
hold the Purchased Certificate is an “insurance company general account” (within the meaning of DOL Prohibited
Transaction Class Exemption (“PTCE”) 95-60), and the conditions in Sections I and III of PTCE 95-60 have been
satisfied.


___      The
Purchaser has delivered to Washington Mutual and the Trustee a Benefit Plan Opinion (as defined in Section 1.01 of the Pooling and
Servicing Agreement, dated as of January 1, 2005, by and among Washington Mutual, the Trustee and the Delaware Trustee thereunder,
and relating to the Trust).


IN WITNESS WHEREOF, the Purchaser has caused this instrument to be duly executed on its behalf, by its duly
authorized officer this _____ day of __________________, 20__.


[Purchaser]


By:
                                                     


      Its:

Personally appeared before me ______________________, known or proved to me to be the same person who executed the foregoing
instrument and to be a ________________ of the Purchaser, and acknowledged to me that (s)he executed the same as his/her free act
and deed and as the free act and deed of the Purchaser.


SUBSCRIBED and SWORN to before me this
day of ____________, 20__.



                                                                                   


             Notary
Public


 












   Exhibit O


BENEFIT PLAN
AFFIDAVIT


Deutsche Bank
National Trust Company, as Trustee (the “Trustee”)

1761 East St. Andrew Place

Santa Ana, CA 92705

Attn: Trust Administration WA05A1


Washington Mutual Mortgage Securities Corp. (“Washington Mutual”)

75 North Fairway Drive

Vernon Hills, IL  60061


 


RE:       CLASS [B-1][B-2][B-3] CERTIFICATES (THE “PURCHASED
CERTIFICATES”)



ISSUED BY WaMu MORTGAGE PASS-THROUGH CERTIFICATES SERIES 2005-AR1


TRUST (THE
“TRUST”)


Under penalties of perjury, I,
_____________________, declare that, to the best of my knowledge and belief, the following representations are true, correct and
complete; and


1.         That I am the _______________ of __________________ (the
“Purchaser”), whose taxpayer identification number is  ___________, and on behalf of which I have the authority to
make this affidavit.


2.         That the Purchaser is acquiring a Purchased Certificate representing an
interest in the assets of the Trust.


3.         That the Purchaser satisfies the condition in the paragraph marked below
[mark one paragraph only]:


___
     The Purchaser is not an employee benefit or other plan subject to the prohibited transaction provisions of
the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), or Section 4975 of the Internal Revenue Code
of 1986, as amended (a “Plan”), or any other person (including an investment manager, a named fiduciary or a trustee of
any such Plan) acting, directly or indirectly, on behalf of or purchasing the Purchased Certificate with “plan assets”
of, any Plan within the meaning of the Department of Labor (“DOL”) regulation at 29 C.F.R. Section
2510.3-101.


___      The Purchaser is an insurance company, the source of funds to be used by it to acquire or
hold the Purchased Certificate is an “insurance company general account” (within the meaning of DOL Prohibited
Transaction Class Exemption (“PTCE”) 95-60), and the conditions in Sections I and III of PTCE 95-60 have been
satisfied.


___      The Purchased Certificate was rated “BBB-” or better (or its equivalent) by at
least one of the Rating Agencies (as defined in Section 1.01 of the Pooling and Servicing Agreement (the “Pooling and
Servicing Agreement”), dated as of January 1, 2005, by and among Washington Mutual, the Trustee and the Delaware Trustee
thereunder, and relating to the Trust) at the time of Purchaser’s acquisition of the Purchased Certificate (or interest
therein).


___      The
Purchaser has delivered to Washington Mutual and the Trustee a Benefit Plan Opinion (as defined in Section 1.01 of the Pooling and
Servicing Agreement).


IN WITNESS WHEREOF, the Purchaser has caused this instrument to be duly executed on its behalf, by its duly
authorized officer this _____ day of __________________, 20__.


[Purchaser]


By:
                                                     


      Its:




Personally appeared before me ______________________, known or proved to me to be the same person who executed the foregoing
instrument and to be a ________________ of the Purchaser, and acknowledged to me that (s)he executed the same as his/her free act
and deed and as the free act and deed of the Purchaser.


SUBSCRIBED and SWORN to before me this
day of ____________, 20__.



                                                                                   


             Notary
Public


 












     
           Exhibit P


BENEFIT PLAN
AFFIDAVIT


Deutsche Bank
National Trust Company, as Trustee (the “Trustee”)

1761 East St. Andrew Place

Santa Ana, CA 92705

Attn: Trust Administration WA05A1


Washington Mutual Mortgage Securities Corp. (“Washington Mutual”)

75 North Fairway Drive

Vernon Hills, IL  60061


 


RE:       CLASS Y CERTIFICATES (THE “PURCHASED CERTIFICATES”)



ISSUED BY WaMu MORTGAGE PASS-THROUGH CERTIFICATES SERIES 2005-AR1


TRUST (THE
“TRUST”)


Under penalties of perjury, I,
_____________________, declare that, to the best of my knowledge and belief, the following representations are true, correct and
complete; and


1.         That I am the _______________ of __________________ (the
“Purchaser”), whose taxpayer identification number is  ___________, and on behalf of which I have the authority to
make this affidavit.


2.         That the Purchaser is acquiring a Purchased Certificate representing an
interest in the assets of the Trust.


3.         That the Purchaser satisfies the condition in the paragraph marked below
[mark one paragraph only]:


___      The
Purchaser is not an employee benefit plan or other plan subject to the prohibited transaction provisions of the Employee Retirement
Income Security Act of 1974, as amended, or Section 4975 of the Internal Revenue Code of 1986, as amended (a “Plan”),
or any other person (including an investment manager, a named fiduciary or a trustee of any Plan) acting, directly or indirectly,
on behalf of, or purchasing any of the Purchased Certificates with “plan assets” of, any Plan within the meaning of the
Department of Labor (“DOL”) regulation at 29 C.F.R. Section 2510.3-101.


___      The
Purchaser has delivered to Washington Mutual and the Trustee a Benefit Plan Opinion (as defined in Section 1.01 of the Pooling and
Servicing Agreement, dated as of January 1, 2005, by and among Washington Mutual, the Trustee and the Delaware Trustee thereunder,
and relating to the Trust).


IN WITNESS WHEREOF, the Purchaser has caused this instrument to be duly executed on its behalf, by its duly
authorized officer this _____ day of __________________, 20__.


[Purchaser]


By:
                                                     


      Its:




Personally appeared before me ______________________, known or proved to me to be the same person who executed the foregoing
instrument and to be a ________________ of the Purchaser, and acknowledged to me that (s)he executed the same as his/her free act
and deed and as the free act and deed of the Purchaser.


SUBSCRIBED and SWORN to before me this
day of ____________, 20__.



                                                                                   


                                                                                                           
Notary Public