**UNITED STATESSECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM 10-K**

(Mark One)

**x****  ANNUAL REPORT PURSUANT TO SECTION13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934**

**For the fiscal year ended December 31, 2017or**

**o**** ****TRANSITIONREPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934**

**For the transition period from _____ to _____Commission file number of the issuing entity: 333-206703-01**

**Central Index Key Number of the issuing entity:0001655153**

**CSAIL 2015-C4 Commercial MortgageTrust**

**(exact name of the issuing entity as specified in itscharter)**

** **

**Central Index Key Number of the depositor: 0000802106**

**Credit Suisse First Boston MortgageSecurities Corp.**

**(exact name of the depositor as specified in its charter)**

** **

**Central Index Key Number of the sponsor: 0001628601**

**Column Financial, Inc.**

**(exact name of the sponsor as specified in its charter)**

** **

**Central Index Key Number of the sponsor: 0001632269**

**Benefit Street Partners CRE FinanceLLC**

**(exact name of the sponsor as specified in its charter)**

** **

**Central Index Key Number of the sponsor: 0001666643**

**Walker & Dunlop CommercialProperty Funding I CS, LLC**

**(exact name of the sponsor as specified in its charter)**

** **

**Central Index Key Number of the sponsor: 0001505494**

**The Bancorp Bank**

**(exact name of the sponsor as specified in its charter)**

** **

**Central Index Key Number of the sponsor: 0001576832**

**MC-Five Mile Commercial MortgageFinance LLC**

**(exact name of the sponsor as specified in its charter)**

** **

| **New York****(State or other jurisdiction of  incorporation or organization of**

**the issuing entity)** | **38-3984607**

**38-3984608**

**(I.R.S. Employer**

**Identification Numbers)** |
|------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------|

**c/o Wells Fargo Bank, National Association**

**as Certificate Administrator**

**9062 Old Annapolis Road**

**Columbia, MD**

**(Address of principalexecutive offices of the issuing entity)**

**21045**

**(Zip Code)**

**Registrant’s telephone number,including area code:**

**(212) 272-6858**

Securities registered pursuant to Section 12(b) of the Act:None.

Securities registered pursuant to Section 12(g) of the Act:None.

Indicate by check mark if the registrant is a well-knownseasoned issuer, as defined in Rule 405 of the Securities Act. o Yes ⌧No

Indicate by check mark if the registrant is not required tofile reports pursuant to Section 13 or Section 15(d) of the Act. o Yes ⌧No

Indicate by check mark whether the registrant (1) has filedall reports required to be filed by Section 13 or 15(d) of the SecuritiesExchange Act of 1934 during the preceding 12 months (or for such shorter periodthat the registrant was required to file such reports), and (2) has beensubject to such filing requirements for the past 90 days. ⌧ Yes oNo

Indicate by check mark whether the registrant has submittedelectronically and posted on its corporate Web site, if any, every InteractiveData File required to be submitted and posted pursuant to Rule 405 ofRegulation S-T (Section 232.405 of this chapter) during the preceding 12 months(or for such shorter period that the registrant was required to submit and postsuch files).

Not applicable.

Indicate by check mark if disclosure of delinquent filerspursuant to Item 405 of Regulation S-K (Section 229.405 of this chapter) is notcontained herein, and will not be contained, to the best of registrant’sknowledge, in definitive proxy or information statements incorporated byreference in Part III of this Form 10-K or any amendment to this Form 10-K.

Not applicable.

Indicate by check mark whether the registrant is a largeaccelerated filer, an accelerated filer, a non-accelerated filer, smallerreporting company or an emerging growth company. See the definitions of “largeaccelerated filer”, “accelerated filer”, “smaller reporting company”, and“emerging growth company” in Rule 12b-2 of the Exchange Act.

Large acceleratedfiler        o                                                                                                       Acceleratedfiler                                     o

Non-acceleratedfiler          ⌧  (Do not check ifa smaller reporting company)                          Smaller reporting company                    o

                                                                                                                                                       Emerging growthcompany                    o

If an emerging growth company, indicate by check mark if theregistrant has elected not to use the extended transition period for complyingwith any new or revised financial accounting standards provided pursuant toSection 13(a) of the ExchangeAct.                                            o

Indicate by check mark whether the registrant is a shellcompany (as defined in Rule 12b-2 of the Act). oYes ⌧ No

State the aggregate market value of the voting and non-votingcommon equity held by non-affiliates computed by reference to the price atwhich the common equity was last sold, or the average bid and asked price ofsuch common equity, as of the last business day of the registrant’s mostrecently completed second fiscal quarter.

Not applicable.

Indicate by check mark whether the registrant has filed alldocuments and reports required to be filed by Section 12, 13 or 15(d) of theSecurities Exchange Act of 1934 subsequent to the distribution of securitiesunder a plan confirmed by a court. oYes oNo

Not applicable.

Indicate the number of shares outstanding of each of theregistrant’s classes of common stock, as of the latest practicable date.

Not applicable.

**DOCUMENTS INCORPORATED BY REFERENCE**

** **

List hereunder the following documents if incorporated byreference and the Part of the Form 10-K (e.g., Part I, Part II, etc.) intowhich the document is incorporated: (1) Any annual report to security holders;(2) Any proxy or information statement; and (3) Any prospectus filed pursuantto Rule 424(b) or (c) under the Securities Act of 1933. The listed documentsshould be clearly described for identification purposes (e.g., annual report tosecurity holders for fiscal year ended December 24, 1980).

Not applicable.

 

 

The Exhibit Index describesexhibits provided by certain parties (in their capacities indicated on theExhibit Index) with respect to the Arizona Grand Resort & Spa MortgageLoan, which constituted approximately 4.8% of the asset pool of the issuingentity as of its cut-off date. The Arizona Grand Resort & Spa MortgageLoan is an asset of the issuing entity and is part of a loan combination thatincludes the Arizona Grand Resort & Spa Mortgage Loan and one other *paripassu* loan, which is not an asset of the issuing entity. The other *paripassu* portion of the loan combination was securitized in the CSAIL 2015-C3Commercial Mortgage Trust transaction, Commission File Number 333-199921-03(the “CSAIL 2015-C3 Transaction”). This loan combination, including theArizona Grand Resort & Spa Mortgage Loan, is being serviced andadministered pursuant to the pooling and servicing agreement for the CSAIL2015-C3 Transaction, which is incorporated by reference as Exhibit 4.2 to thisAnnual Report on Form 10-K. Midland Loan Services, a Division of PNC Bank,National Association is the master servicer under the pooling and servicingagreement for the CSAIL 2015-C3 Transaction. The responsibilities of MidlandLoan Services, a Division of PNC Bank, National Association, as primaryservicer of this loan combination with respect to the issuing entity, aresubsumed within its responsibilities as master servicer under the pooling andservicing agreement for the CSAIL 2015-C3 Transaction. Thus, the servicer compliancestatement provided by Midland Loan Services, a Division of PNC Bank, NationalAssociation, as master servicer under such pooling and servicing agreement,encompasses its roles as both master servicer and primary servicer with respectto this loan combination.

Wells Fargo Bank, NationalAssociation is the master servicer and certificate administrator of themortgage loans serviced under the Pooling and Servicing Agreement and thecertificate administrator of the Arizona Grand Resort & Spa Mortgage Loan.As a result, Wells Fargo Bank, National Association is a “servicer” as definedin Item 1108(a)(2)(iii) of Regulation AB, in the capacities described above,because it is servicing mortgage loans that constituted 10% or more of theassets of the issuing entity as of its cut-off date. The assessments ofcompliance with applicable servicing criteria, accountants’ attestation reportsand servicer compliance statements delivered by Wells Fargo Bank, NationalAssociation in the capacities described above are listed in the Exhibit Index.

Wells Fargo Bank, National Association is the custodian ofthe mortgage loans serviced under the Pooling and Servicing Agreement and thetrustee and custodian of the Arizona Grand Resort & Spa Mortgage Loan. As aresult, Wells Fargo Bank, National Association is a servicing functionparticipant in the capacities described above, because it is servicing mortgageloans that constituted 5% or more of the assets of the issuing entity as of itscut-off date. The assessments of compliance with applicable servicing criteriaand accountants’ attestation reports delivered by Wells Fargo Bank, NationalAssociation in the capacities described above are listed in the Exhibit Index.

Midland Loan Services, a Divisionof PNC Bank, National Association is the special servicer of the mortgage loansserviced under the Pooling and Servicing Agreement and the primary servicer ofthe Arizona Grand Resort & Spa Mortgage Loan. As a result, Midland LoanServices, a Division of PNC Bank, National Association is a “servicer” asdefined in Item 1108(a)(2)(iii) of Regulation AB, in the capacities describedabove, because it is servicing mortgage loans that constituted 10% or more ofthe assets of the issuing entity as of its cut-off date. The assessments of compliancewith applicable servicing criteria, accountants’ attestation reports andservicer compliance statements delivered by Midland Loan Services, a Divisionof PNC Bank, National Association in the capacities described above are listedin the Exhibit Index.

Pentalpha Surveillance LLC is the operating advisor of themortgage loans serviced under the Pooling and Servicing Agreement and theArizona Grand Resort & Spa Mortgage Loan. As a result, PentalphaSurveillance LLC is a servicing function participant in the capacitiesdescribed above, because it is servicing mortgage loans that constituted 5% ormore of the assets of the issuing entity as of its cut-off date. Theassessments of compliance with applicable servicing criteria and accountants’attestation reports delivered by Pentalpha Surveillance LLC in the capacitiesdescribed above are listed in the Exhibit Index.

Wilmington Trust, NationalAssociation acts as trustee of the mortgage loans serviced under the Poolingand Servicing Agreement. Pursuant to the Pooling and Servicing Agreement, thetrustee is required to provide an assessment of compliance with applicableservicing criteria solely with respect to Item 1122(d)(2)(iii) of Regulation AB(regarding advances of funds or guarantees regarding collections, cash flows ordistributions, and any interest or other fees charged for such advances, aremade, reviewed and approved as specified in the transaction agreements).However, during the reporting period, the trustee did not perform any servicingfunction with respect to the servicing criteria specified in Item1122(d)(2)(iii) of Regulation AB. The master servicer or the special servicer,to the extent required, performed the servicing function identified withrespect to Item 1122(d)(2)(iii) of Regulation AB, and each such party includedItem 1122(d)(2)(iii) of Regulation AB in the assessment of compliance withapplicable servicing criteria and accountant’s attestation report for thesubject transaction. As a result, this Annual Report on Form 10-K does notinclude an assessment of compliance with applicable servicing criteria of thetrustee. One or more other servicers of the mortgage loans serviced under thePooling and Servicing Agreement have delivered one or more assessments ofcompliance with respect to Item 1122(d)(2)(iii) of Regulation AB.

This Annual Report on Form 10-Kincludes assessments of compliance with applicable servicing criteria andaccountants’ attestation reports from CoreLogic Commercial Real EstateServices, Inc. and National Tax Search, LLC. These entities were engagedby the master servicer under the Pooling and Servicing Agreement to remit taxpayments received from the escrow accounts of borrowers to local taxingauthorities, to report tax amounts due, to verify tax parcel information, andto verify non-escrow tax payments. These servicing functions are includedwithin the servicing criteria set forth in Items 1122(d)(4)(xi) and1122(d)(4)(xii) of Regulation AB. Therefore, under the principles-baseddefinition of “servicer” set forth in Item 1101(j) of Regulation AB that looksto the functions that an entity performs, these vendors are “servicers” for thepurposes of Item 1122 of Regulation AB. *See* Compliance andDisclosure Interpretations, Section 301.01 (Item 1101(j)).

With respect to the *pari passu*loan combination that includes the Arizona Grand Resort & Spa MortgageLoan, (i) the report on assessment of compliance with servicing criteria andattestation report on assessment of compliance with servicing criteria ofRialto Capital Advisors, LLC as special servicer of the Arizona Grand Resort& Spa Mortgage Loan, listed on the Exhibit Index is omitted from thisAnnual Report on Form 10-K as it is not required to be included on this AnnualReport on Form 10-K per Instruction 3 to Item 1122 of Regulation AB because itis a party performing activities that address servicing criteria relating to 5%or less of the assets of the issuing entity; and (ii) the servicer compliancestatement of Rialto Capital Advisors, LLC as special servicer of the ArizonaGrand Resort & Spa Mortgage Loan, listed on the Exhibit Index is omittedfrom this Annual Report on Form 10-K as it is not required by Item 1123 ofRegulation AB to be included on this Annual Report on Form 10-K because it isan unaffiliated party that is not a “servicer” that meets the criteria in Item1108(a)(2)(i) through (iii) of Regulation AB.

**PART I**

**Item 1. Business.**

Omitted.

**Item 1A. Risk Factors.**

Omitted.

**Item 1B. Unresolved Staff Comments.**

None.

**Item 2. Properties.**

Omitted.

**Item 3. Legal Proceedings.**

Omitted.

**Item 4. Mine Safety Disclosures.**

Not applicable.

**PART II**

**Item 5. Market for Registrant’s Common Equity, RelatedStockholder Matters and Issuer Purchases of Equity Securities.**

Omitted.

**Item 6. Selected Financial Data.**

Omitted.

**Item 7. Management’s Discussion and Analysis of FinancialCondition and Results of Operations.**

Omitted.

**Item 7A. Quantitative and Qualitative Disclosures AboutMarket Risk.**

Omitted.

**Item 8. Financial Statements and Supplementary Data.**

Omitted.

**Item 9. Changes in and Disagreements With Accountants onAccounting and Financial Disclosure.**

Omitted.

**Item 9A. Controls and Procedures.**

Omitted.

**Item 9B. Other Information.**

None.

**PART III**

**Item 10. Directors, Executive Officers and CorporateGovernance.**

Omitted.

**Item 11. Executive Compensation.**

Omitted.

**Item 12. Security Ownership of Certain Beneficial Ownersand Management and Related Stockholder Matters.**

Omitted.

**Item 13. Certain Relationships and Related Transactions,and Director Independence.**

Omitted.

**Item 14. Principal Accounting Fees and Services.**

Omitted.

**ADDITIONAL DISCLOSURE ITEMS FOR REGULATION AB**

**Item 1112(b) of Regulation AB, Significant ObligorFinancial Information.**

The Fairmont Orchid Mortgage Loan (Loan # 1 on Annex A of theprospectus supplement of the registrant relating to the issuing entity filed onNovember 25, 2015 pursuant to Rule 424(b)(5)) constitutes a significant obligorwithin the meaning of Item 1101(k)(2) of Regulation AB as disclosed in theprospectus supplement. In accordance with Item 1112(b) of Regulation AB, themost recent unaudited net operating income of the significant obligor was$21,440,578.00 for the twelve- month period ended December 31, 2017.

**Item 1114(b)(2) of Regulation AB, Significant EnhancementProvider Financial Information.**

No entity or group of affiliated entities provides any external creditenhancement or other support for the certificates within this transaction asdescribed under Item 1114(a) of Regulation AB.

**Item 1115(b) of Regulation AB, Certain DerivativesInstruments (Financial Information).**

No entity or group of affiliated entities provides anyderivative instruments or other support for the certificates within thistransaction as described under Item 1115 of Regulation AB.

**Item 1117 of Regulation AB, Legal Proceedings.**

The registrant knows of no material pending legal proceedinginvolving the trust or any party related to the trust, other than routinelitigation incidental to the duties of those respective parties, and thefollowing, with respect to Wells Fargo Bank, National Association, ascertificate administrator, custodian and trustee:

On June 18, 2014, a group of institutional investors filed acivil complaint in the Supreme Court of the State of New York, New York County,against Wells Fargo Bank, N.A. (“Wells Fargo Bank”) in its capacity as trusteeunder 276 residential mortgage backed securities (“RMBS”) trusts, which waslater amended on July 18, 2014, to increase the number of trusts to 284 RMBS trusts.On November 24, 2014, the plaintiffs filed a motion to voluntarily dismiss thestate court action without prejudice. That same day, a group of institutionalinvestors filed a putative class action complaint in the United States DistrictCourt for the Southern District of New York (the “District Court”) againstWells Fargo Bank, alleging claims against the bank in its capacity as trusteefor 274 RMBS trusts (the “Federal Court Complaint”). In December 2014, theplaintiffs’ motion to voluntarily dismiss their original state court action wasgranted. As with the prior state court action, the Federal Court Complaint isone of six similar complaints filed contemporaneously against RMBS trustees(Deutsche Bank, Citibank, HSBC, Bank of New York Mellon and US Bank) by a groupof institutional investor plaintiffs. The Federal Court Complaint against WellsFargo Bank alleges that the trustee caused losses to investors and assertscauses of action based upon, among other things, the trustee's alleged failureto: (i) notify and enforce repurchase obligations of mortgage loan sellers forpurported breaches of representations and warranties, (ii) notify investors ofalleged events of default, and (iii) abide by appropriate standards of carefollowing alleged events of default. Relief sought includes money damages in anunspecified amount, reimbursement of expenses, and equitable relief. Othercases alleging similar causes of action have been filed against Wells FargoBank and other trustees in the District Court by RMBS investors in these andother transactions, and these cases against Wells Fargo Bank are proceedingbefore the same District Court judge. A similar complaint was also filed May27, 2016 in New York state court by a different plaintiff investor. On January19, 2016, an order was entered in connection with the Federal Court Complaintin which the District Court declined to exercise jurisdiction over 261 trustsat issue in the Federal Court Complaint; the District Court also allowedplaintiffs to file amended complaints as to the remaining, non-dismissedtrusts, if they so chose, and three amended complaints have been filed. OnDecember 17, 2016, the investor plaintiffs in the 261 trusts dismissed from theFederal Court Complaint filed a new complaint in New York state court (the“State Court Complaint”). In September 2017, Royal Park Investments SA/NV(“Royal Park”), one of the plaintiffs in the District Court cases against WellsFargo Bank, filed a putative class action complaint relating to two trusts seekingdeclaratory and injunctive relief and money damages based on Wells Fargo Bank’sindemnification from trust funds for legal fees and expenses Wells Fargo Bankincurs or has incurred in defending the District Court case filed by RoyalPark. With respect to the foregoing litigations, Wells Fargo Bank believesplaintiffs' claims are without merit and intends to contest the claimsvigorously, but there can be no assurances as to the outcome of the litigationsor the possible impact of the litigations on Wells Fargo Bank or the RMBStrusts.

**Item 1119 of Regulation AB, Affiliations and CertainRelationships and Related Transactions.**

The information regarding this Item has been previouslyprovided in a prospectus supplement of the Registrant relating to the issuingentity filed on November 25, 2015 pursuant to Rule 424(b)(5).

**Item 1122 of Regulation AB, Compliance with ApplicableServicing Criteria.**

The reports on assessments of compliance with the servicingcriteria for asset-backed securities and related attestation reports on suchassessments of compliance with respect to the mortgage loans are attachedhereto under Item 15 to this Annual Report on Form 10-K. Attached as Exhibit Oto the Pooling and Servicing Agreement incorporated by reference as Exhibit 4.1to this Annual Report on Form 10-K is a chart identifying the entitiesparticipating in a servicing function for the transaction responsible for eachapplicable servicing criteria set forth in Item 1122(d).

The reports on assessments of compliance with the servicingcriteria for asset-backed securities and related attestation reports on suchassessments of compliance with respect to the Arizona Grand Resort & SpaMortgage Loan, which is being serviced and administered pursuant to the poolingand servicing agreement for the CSAIL 2015-C3 Transaction, are attached heretounder Item 15 to this Annual Report on Form 10-K. Attached as Exhibit O to thepooling and servicing agreement for the CSAIL 2015-C3 Transaction incorporatedby reference as Exhibit 4.2 to this Annual Report on Form 10-K is a chartidentifying the entities participating in a servicing function for the CSAIL2015-C3 Transaction responsible for each applicable servicing criteria setforth in Item 1122(d).

**Item 1123 of Regulation AB, Servicer Compliance Statement.**

The servicer compliance statements are attached as Exhibitsto this Annual Report on Form 10-K.

**PART IV**

**Item 15. Exhibits, Financial Statement Schedules**

(a) The following is a list of documents filed as part ofthis Annual Report on Form 10-K:

(1) Not applicable

(2) Not applicable

(3) See below

 

4.1          Pooling and Servicing Agreement, dated as of November 1, 2015, by and amongCredit Suisse First Boston Mortgage Securities Corp., as Depositor, Wells FargoBank, National Association, as Master Servicer, Midland Loan Services, aDivision of PNC Bank, National Association, as Special Servicer, PentalphaSurveillance LLC, as Operating Advisor, Wells Fargo Bank, National Association,as Certificate Administrator and Wilmington Trust, National Association, asTrustee (filed as Exhibit 4.1 to the registrant’s Current Report on Form 8-Kfiled on November 25, 2015 under Commission File No. 333-206703-01 andincorporated by reference herein)

4.2          Pooling and Servicing Agreement, dated as of August 1, 2015, by and amongCredit Suisse First Boston Mortgage Securities Corp., as Depositor, MidlandLoan Services, a Division of PNC Bank, National Association, as MasterServicer, Rialto Capital Advisors, LLC, as Special Servicer, Pentalpha SurveillanceLLC, as Operating Advisor, Wells Fargo Bank, National Association, asCertificate Administrator and Wells Fargo Bank, National Association, asTrustee (filed as Exhibit 4.2 to the registrant’s Current Report on Form 8-Kfiled on November 25, 2015 under Commission File No. 333-206703-01 andincorporated by reference herein)

4.3          Co-Lender Agreement, dated as of August 18, 2015, by and among ColumnFinancial, Inc., as Initial Note A-1 Holder and Column Financial, Inc., asInitial Note A-2 Holder (filed as Exhibit 4.3 to the registrant’s CurrentReport on Form 8-K filed on November 25, 2015 under Commission File No.333-206703-01 and incorporated by reference herein)

31           Rule 13a-14(d)/15d-14(d) Certifications.

33           Reports on assessment of compliance with servicing criteria for asset-backedsecurities.

33.1        Wells Fargo Bank, National Association, as Master Servicer

33.2        Midland Loan Services, a Division of PNC Bank, National Association, as SpecialServicer

33.3        Wilmington Trust, National Association, as Trustee (Omitted. See ExplanatoryNotes.)

33.4        Wells Fargo Bank, National Association, as Certificate Administrator

33.5        Wells Fargo Bank, National Association, as Custodian

33.6        Pentalpha Surveillance LLC, as Operating Advisor

33.7        CoreLogic Commercial Real Estate Services, Inc., as Servicing FunctionParticipant

33.8        National Tax Search, LLC, as Servicing Function Participant

33.9        Midland Loan Services, a Division of PNC Bank, National Association, as PrimaryServicer of the Arizona Grand Resort & Spa Mortgage Loan (see Exhibit 33.2)

33.10      Rialto Capital Advisors, LLC, as Special Servicer of the Arizona Grand Resort& Spa Mortgage Loan (Omitted. See Explanatory Notes.)

33.11      Wells Fargo Bank, National Association, as Trustee and CertificateAdministrator of the Arizona Grand Resort & Spa Mortgage Loan (see Exhibit33.4)

33.12      Wells Fargo Bank, National Association, as Custodian of the Arizona GrandResort & Spa Mortgage Loan (see Exhibit 33.5)

33.13      Pentalpha Surveillance LLC, as Operating Advisor of the Arizona Grand Resort& Spa Mortgage Loan (see Exhibit 33.6)

34           Attestationreports on assessment of compliance with servicing criteria for asset-backedsecurities.

34.1        Wells Fargo Bank, National Association, as Master Servicer

34.2        Midland Loan Services, a Division of PNC Bank, National Association, as SpecialServicer

34.3        Wilmington Trust, National Association, as Trustee (Omitted. See ExplanatoryNotes.)

34.4        Wells Fargo Bank, National Association, as Certificate Administrator

34.5        Wells Fargo Bank, National Association, as Custodian

34.6        Pentalpha Surveillance LLC, as Operating Advisor

34.7        CoreLogic Commercial Real Estate Services, Inc., as Servicing FunctionParticipant

34.8        National Tax Search, LLC, as Servicing Function Participant

34.9        Midland Loan Services, a Division of PNC Bank, National Association, as PrimaryServicer of the Arizona Grand Resort & Spa Mortgage Loan (see Exhibit 34.2)

34.10      Rialto Capital Advisors, LLC, as Special Servicer of the Arizona Grand Resort& Spa Mortgage Loan (Omitted. See Explanatory Notes.)

34.11      Wells Fargo Bank, National Association, as Trustee and CertificateAdministrator of the Arizona Grand Resort & Spa Mortgage Loan (see Exhibit34.4)

34.12      Wells Fargo Bank, National Association, as Custodian of the Arizona GrandResort & Spa Mortgage Loan (see Exhibit 34.5)

34.13      Pentalpha Surveillance LLC, as Operating Advisor of the Arizona Grand Resort& Spa Mortgage Loan (see Exhibit 34.6)

35           Servicer compliance statements.

35.1        Wells Fargo Bank, National Association, as Master Servicer

35.2        Midland Loan Services, a Division of PNC Bank, National Association, as SpecialServicer

35.3        Wells Fargo Bank, National Association, as Certificate Administrator

35.4        Midland Loan Services, a Division of PNC Bank, National Association, as PrimaryServicer of the Arizona Grand Resort & Spa Mortgage Loan (see Exhibit 35.2)

35.5        Rialto Capital Advisors, LLC, as Special Servicer of the Arizona Grand Resort& Spa Mortgage Loan (Omitted. See Explanatory Notes.)

35.6        Wells Fargo Bank, National Association, as Certificate Administrator of theArizona Grand Resort & Spa Mortgage Loan (see Exhibit 35.3)

99.1        Mortgage Loan Purchase Agreement, dated as of November 1, 2015, between CreditSuisse First Boston Mortgage Securities Corp. and Column Financial, Inc. (filedas Exhibit 99.1 to the registrant’s Current Report on Form 8-K filed onNovember 25, 2015 under Commission File No. 333-206703-01 and incorporated byreference herein)

99.2        Mortgage Loan Purchase Agreement, dated as of November 1, 2015, between CreditSuisse First Boston Mortgage Securities Corp. and Benefit Street Partners CREFinance LLC (filed as Exhibit 99.2 to the registrant’s Current Report on Form8-K filed on November 25, 2015 under Commission File No. 333-206703-01 andincorporated by reference herein)

99.3        Mortgage Loan Purchase Agreement, dated as of November 1, 2015, among CreditSuisse First Boston Mortgage Securities Corp., Walker & Dunlop CommercialProperty Funding I CS, LLC and Walker & Dunlop Commercial Property Funding,LLC (filed as Exhibit 99.3 to the registrant’s Current Report on Form 8-K filedon November 25, 2015 under Commission File No. 333-206703-01 and incorporatedby reference herein)

99.4        Mortgage Loan Purchase Agreement, dated as of November 1, 2015, between CreditSuisse First Boston Mortgage Securities Corp. and The Bancorp Bank (filed asExhibit 99.4 to the registrant’s Current Report on Form 8-K filed on November25, 2015 under Commission File No. 333-206703-01 and incorporated by referenceherein)

99.5        Mortgage Loan Purchase Agreement, dated as of November 1, 2015, between CreditSuisse First Boston Mortgage Securities Corp. and MC-Five Mile CommercialMortgage Finance LLC (filed as Exhibit 99.5 to the registrant’s Current Reporton Form 8-K filed on November 25, 2015 under Commission File No. 333-206703-01and incorporated by reference herein)

 (b)  The exhibits required to be filed by theRegistrant pursuant to Item 601 of Regulation S-K are listed above and in theExhibit Index that immediately follows the signature page hereof.

(c)    Not Applicable.

 

**SIGNATURES**

Pursuant to the requirements of Section 13 or 15(d) of the SecuritiesExchange Act of 1934, the registrant has duly caused this report to be signedon its behalf by the undersigned, thereunto duly authorized.

Credit Suisse First Boston MortgageSecurities Corp.(Depositor)

/s/ PatrickA. Remmert Jr., President

Patrick A.Remmert Jr., President

(senior officer in charge ofsecuritization of the depositor)

Date: March 22, 2018

Exhibit Index

Exhibit No. 

 

4.1          Poolingand Servicing Agreement, dated as of November 1, 2015, by and among CreditSuisse First Boston Mortgage Securities Corp., as Depositor, Wells Fargo Bank,National Association, as Master Servicer, Midland Loan Services, a Division ofPNC Bank, National Association, as Special Servicer, Pentalpha SurveillanceLLC, as Operating Advisor, Wells Fargo Bank, National Association, asCertificate Administrator and Wilmington Trust, National Association, asTrustee (filed as Exhibit 4.1 to the registrant’s Current Report on Form 8-Kfiled on November 25, 2015 under Commission File No. 333-206703-01 andincorporated by reference herein)

4.2          Poolingand Servicing Agreement, dated as of August 1, 2015, by and among Credit SuisseFirst Boston Mortgage Securities Corp., as Depositor, Midland Loan Services, aDivision of PNC Bank, National Association, as Master Servicer, Rialto CapitalAdvisors, LLC, as Special Servicer, Pentalpha Surveillance LLC, as OperatingAdvisor, Wells Fargo Bank, National Association, as Certificate Administratorand Wells Fargo Bank, National Association, as Trustee (filed as Exhibit 4.2 tothe registrant’s Current Report on Form 8-K filed on November 25, 2015 underCommission File No. 333-206703-01 and incorporated by reference herein)

4.3          Co-LenderAgreement, dated as of August 18, 2015, by and among Column Financial, Inc., asInitial Note A-1 Holder and Column Financial, Inc., as Initial Note A-2 Holder(filed as Exhibit 4.3 to the registrant’s Current Report on Form 8-K filed onNovember 25, 2015 under Commission File No. 333-206703-01 and incorporated byreference herein)

31           Rule 13a-14(d)/15d-14(d) Certifications.

33           Reports on assessment of compliance with servicing criteria for asset-backed securities.

 

33.1        Wells Fargo Bank,National Association, as Master Servicer

33.2        Midland Loan Services,a Division of PNC Bank, National Association, as Special Servicer

33.3        Wilmington Trust, National Association, as Trustee(Omitted. See Explanatory Notes.)

33.4        Wells Fargo Bank,National Association, as Certificate Administrator

33.5        Wells Fargo Bank,National Association, as Custodian

33.6        Pentalpha SurveillanceLLC, as Operating Advisor

33.7        CoreLogic CommercialReal Estate Services, Inc., as Servicing Function Participant

33.8        National Tax Search,LLC, as Servicing Function Participant

33.9        Midland Loan Services,a Division of PNC Bank, National Association, as Primary Servicer of theArizona Grand Resort & Spa Mortgage Loan (see Exhibit 33.2) 

33.10       Rialto Capital Advisors, LLC, as Special Servicer of theArizona Grand Resort & Spa Mortgage Loan (Omitted. See Explanatory Notes.)

33.11       Wells Fargo Bank, NationalAssociation, as Trustee and Certificate Administrator of the Arizona GrandResort & Spa Mortgage Loan (see Exhibit 33.4) 

33.12       Wells Fargo Bank, NationalAssociation, as Custodian of the Arizona Grand Resort & Spa Mortgage Loan(see Exhibit 33.5) 

33.13       Pentalpha Surveillance LLC,as Operating Advisor of the Arizona Grand Resort & Spa Mortgage Loan (seeExhibit 33.6) 

34           Attestationreports on assessment of compliance with servicing criteria for asset-backedsecurities.

 

34.1        Wells Fargo Bank,National Association, as Master Servicer

34.2        Midland Loan Services,a Division of PNC Bank, National Association, as Special Servicer

34.3        Wilmington Trust, National Association, as Trustee(Omitted. See Explanatory Notes.)

34.4        Wells Fargo Bank,National Association, as Certificate Administrator

34.5        Wells Fargo Bank,National Association, as Custodian

34.6        Pentalpha SurveillanceLLC, as Operating Advisor

34.7        CoreLogic CommercialReal Estate Services, Inc., as Servicing Function Participant

34.8        National Tax Search,LLC, as Servicing Function Participant

34.9        Midland Loan Services,a Division of PNC Bank, National Association, as Primary Servicer of theArizona Grand Resort & Spa Mortgage Loan (see Exhibit 34.2) 

34.10       Rialto Capital Advisors, LLC, as Special Servicer of theArizona Grand Resort & Spa Mortgage Loan (Omitted. See Explanatory Notes.)

34.11       Wells Fargo Bank, NationalAssociation, as Trustee and Certificate Administrator of the Arizona GrandResort & Spa Mortgage Loan (see Exhibit 34.4) 

34.12       Wells Fargo Bank, NationalAssociation, as Custodian of the Arizona Grand Resort & Spa Mortgage Loan(see Exhibit 34.5) 

34.13       Pentalpha Surveillance LLC,as Operating Advisor of the Arizona Grand Resort & Spa Mortgage Loan (seeExhibit 34.6) 

35           Servicer compliance statements.

 

35.1        Wells Fargo Bank,National Association, as Master Servicer

35.2        Midland Loan Services,a Division of PNC Bank, National Association, as Special Servicer

35.3        Wells Fargo Bank,National Association, as Certificate Administrator

35.4        Midland Loan Services,a Division of PNC Bank, National Association, as Primary Servicer of theArizona Grand Resort & Spa Mortgage Loan (see Exhibit 35.2) 

35.5        Rialto Capital Advisors, LLC, as Special Servicer of theArizona Grand Resort & Spa Mortgage Loan (Omitted. See Explanatory Notes.)

35.6        Wells Fargo Bank,National Association, as Certificate Administrator of the Arizona Grand Resort& Spa Mortgage Loan (see Exhibit 35.3) 

99.1        MortgageLoan Purchase Agreement, dated as of November 1, 2015, between Credit SuisseFirst Boston Mortgage Securities Corp. and Column Financial, Inc. (filed asExhibit 99.1 to the registrant’s Current Report on Form 8-K filed on November25, 2015 under Commission File No. 333-206703-01 and incorporated by referenceherein)

99.2        MortgageLoan Purchase Agreement, dated as of November 1, 2015, between Credit Suisse FirstBoston Mortgage Securities Corp. and Benefit Street Partners CRE Finance LLC(filed as Exhibit 99.2 to the registrant’s Current Report on Form 8-K filed onNovember 25, 2015 under Commission File No. 333-206703-01 and incorporated byreference herein)

99.3        MortgageLoan Purchase Agreement, dated as of November 1, 2015, among Credit SuisseFirst Boston Mortgage Securities Corp., Walker & Dunlop Commercial PropertyFunding I CS, LLC and Walker & Dunlop Commercial Property Funding, LLC(filed as Exhibit 99.3 to the registrant’s Current Report on Form 8-K filed onNovember 25, 2015 under Commission File No. 333-206703-01 and incorporated byreference herein)

99.4        MortgageLoan Purchase Agreement, dated as of November 1, 2015, between Credit SuisseFirst Boston Mortgage Securities Corp. and The Bancorp Bank (filed as Exhibit99.4 to the registrant’s Current Report on Form 8-K filed on November 25, 2015under Commission File No. 333-206703-01 and incorporated by reference herein)

99.5        MortgageLoan Purchase Agreement, dated as of November 1, 2015, between Credit SuisseFirst Boston Mortgage Securities Corp. and MC-Five Mile Commercial MortgageFinance LLC (filed as Exhibit 99.5 to the registrant’s Current Report on Form8-K filed on November 25, 2015 under Commission File No. 333-206703-01 andincorporated by reference herein)