<PAGE>   1
                                                                    EXHIBIT 10.5

                                 AMENDMENT NO. 5

                     THE PRINCIPAL SELECT SAVINGS EXCESS PLAN

The Plan named above gives the Company the right to amend it at any time.
According to that right, the Plan is amended as follows:

Effective July 1, 1998,

By striking the paragraph in the DEATH BENEFITS SECTION of Article V and
substituting the following:

     If a Participant dies before his Retirement Date, his Vested Account shall
     be distributed to his Beneficiary in a single sum.

By striking subsections (a) and (b) of the OPTIONAL FORMS OF DISTRIBUTION
SECTION of Article VI and substituting the following:

     The optional forms of retirement benefit shall be the following: a single
     life annuity with a certain period of ten years; a single life annuity with
     installment refund; survivorship life annuity with installment refund and a
     survivorship percentage of 50; and a 120-month fixed period annuity. An
     election under this paragraph may be delayed until the Participant reaches
     his required beginning date under the Associated Plan

     The following optional forms of retirement benefit are also available: a
     single sum payment; an annual distribution equal to any fixed whole
     percentage, not less than 10% and not more than 13% of his Vested Account,
     as elected by the Participant. Such amount shall be payable annually until
     his vested Account is exhausted. Once elected, the percentage will
     not, change. An election under this paragraph may be delayed until the
     Participant reaches his required beginning date under the Associated Plan.

     A form of distribution for retirement benefits shall be available to a
     Participant only if the annual distribution under such form is at least
     equal to the quotient of the Participant's Vested Account as of the date
     distribution is to begin, divided by the life expectancy of the
     Participant, Beneficiary or joint and last survivor expectancy of the
     Participant and Beneficiary, as appropriate. If distribution is in a form
     other than a life annuity, the life expectancy of the Participant may be
     recalculated after the distribution begins, but no more frequently than
     annually. In the case of a Beneficiary who is not the Participant's spouse,
     life expectancy shall be calculated when benefits start and minimum
     payments for any 12-consecutive month period will be based on such life
     expectancy minus the number of whole years since the distribution first
     began. The life expectancy or joint and last survivor expectancy shall be
     computed by use of the return multiples contained in Section 1.72-9 of the
     regulations under the Code.

By striking the first sentence of the first paragraph in the ELECTION PROCEDURES
SECTION of Article VI and substituting the following:

    The Participant shall make any election under this section in the form or
    manner provided for that purpose.

By striking subsections (a) and (b) in the ELECTION PROCEDURES SECTION of
Article VI and substituting the following:


                                       1
<PAGE>   2


     A Participant may elect his Beneficiary and may elect to have retirement
     benefits distributed under any of the optional forms of retirement benefit
     described in the OPTIONAL FORMS OF DISTRIBUTION SECTION of this article.

Effective January 1, 2000,

By striking the following from the Table of Contents:

     Section 9.09 ---- Small Amounts

By striking the AGENT definition in the DEFINITIONS SECTION of Article I and
substituting the following:

     AGENT means an individual who holds a current DD 713 contract or any
     successor full-time contract with the Company and he is one of the
     following:

     -    an agent;

     -    a sales supervisor;

     -    a special marketing developer;

     -    a special brokerage developer;

     -    a special agency assistant; or

     -    an informal agency assistant.

By striking the AGENT'S CONTRACT, GENERAL MANAGER and MANAGEMENT ASSISTANT
definitions from the DEFINITIONS SECTION of Article I.

By striking the second paragraph of the COMPENSATION definition in the
DEFINITIONS SECTION of Article I and substituting the following:

     "Earnings" in this definition means earnings as defined in the definition
     of Compensation or Earnings in the Savings Plan. In determining
     eligibility, Earnings will also include an Eligible Employee's compensation
     with a prior employer if it is earned within the calendar year in which he
     is hired or his contract first becomes effective.

By striking the ELIGIBLE EMPLOYEE definition in the DEFINITIONS SECTION of
Article I and substituting the following:

     ELIGIBLE EMPLOYEE means any Employee, Agent or Field Manager.

By adding the following to the DEFINITIONS SECTION of Article I:

     FIELD MANAGER means:

     (a)  An individual who holds a current DD 713 contract or any successor
          full-time contract with the Company; and

     (b)  Such individual is in one of the following full-time field management
          positions:

          -    management assistant;

          -    management associate;

          -    manager;

          -    co-manager;

          -    assistant general manager;


                                       2
<PAGE>   3

          -    associate general manager;

          -    co-general manager;

          -    general manager;

          -    brokerage manager;

          -    brokerage sales manager; or

          -    brokerage director;

By striking the PAY PERIOD definition from the DEFINITIONS SECTION of Article I.

By striking the first sentence of the first paragraph in subsection (a) of the
COMPANY CONTRIBUTIONS SECTION of Article Ill and substituting the following:

     (a)  Elective Deferral Contributions. The amount of each Elective Deferral
          Contribution for a Participant shall be equal to any percentage (not
          less than 6% nor more than 8%) of his Compensation for the pay period
          (as established by the Company) as elected in his salary deferral
          agreement.

By striking the second paragraph in subsection (a) of the COMPANY CONTRIBUTIONS
SECTION of Article Ill and substituting the following:

     The salary deferral agreement must be effective before the beginning of the
     pay period (as established by the Company) in which Elective Deferral
     Contributions are to start or stop.

By striking the first paragraph in subsection (b) of the COMPANY CONTRIBUTIONS
SECTION of Article Ill and substituting the following:

     (b)  Matching Contributions. The amount of each Matching Contribution made
          by the Company for a Participant shall be equal to 50% of the
          Participant's Elective Deferral Contributions for the pay period (as
          established by the Company). The amount of Matching Contribution made
          by the Company for a Participant shall not exceed 3% of his
          Compensation for such pay period.

By striking the words "and the SMALL AMOUNTS SECTION of Article IX," from the
DEATH BENEFITS SECTION of Article V.

By striking the first sentence of the DISABILITY BENEFITS SECTION of Article V
and substituting the following:

     If a Participant becomes totally and permanently disabled, as defined in
     the Savings Plan, his Vested Account shall be distributed to him in a
     single sum payment.

By adding the following sentence to the end of the first paragraph in Article
VIII:

     Benefits under this Plan will be paid only if the Plan Administrator
     decides, in his discretion, that the applicant is entitled to them.

By striking the SMALL AMOUNTS SECTION of Article IX in its entirety.


                                       3
<PAGE>   4

Effective January 1, 2001:

By striking the SAVINGS PLAN definition in the DEFINITIONS SECTION of Article I
and substituting the following:

     SAVINGS PLAN means the qualified plan(s) as follows:

          The Principal Select Savings Plan for Employees The Principal Select
          Savings Plan for Individual Field

This amendment is made an integral part of the aforesaid Plan and is controlling
over the terms of said Plan with respect to the particular items addressed
expressly herein. All other provisions of the Plan remain unchanged and
controlling.

Unless otherwise stated on any page of this amendment, eligibility for benefits
and the amount of any benefits payable to or on behalf of an individual who is
an Inactive Participant on the effective date(s) stated above, shall be
determined according to the provisions of the aforesaid Plan as in effect on the
day before he became an Inactive Participant.

Signing this amendment, the Company, as plan sponsor, has made the decision to
adopt this plan amendment. The Company is acting in reliance on its own
discretion and on the legal and tax advice of its own advisors, and not that of
any member of the Principal Financial Group or any representative of a member
company of the Principal Financial Group.

Signed this 28th day of December, 2000.


                                             PRINCIPAL LIFE INSURANCE COMPANY

                                             By /s/ LYNN M. GRAVES
                                                --------------------------------

                                             2nd Vice President
                                             -----------------------------------
                                                            Title


                                       4
<PAGE>   5

                      PLAN PAGES AFFECTED BY THIS AMENDMENT

1.   Page 4 - Table of Contents, deleting Small Amounts section

2.   Page 6 - Change definition of Agent and Compensation. Delete def of Agents
     Contract.

3.   Page 7 - Delete def of General Manager; change eligible employee; add Field
     Manager; delete Pay Period.

4.   Page 8 - Delete def of Management Assistant; change def of Savings Plan.

5.   Page 12 - Change to elective deferral language and Company contributions.

6.   Page 34 - Changes to death benefits section and disability benefits
     section.

7.   Page 15 - Change to optional forms of distribution section.

8.   Page 16 - Change to election procedures section.

9.   Page 20 - Delete small amounts section


                                       5
<PAGE>   6

                                 AMENDMENT NO. 4

                    THE PRINCIPAL SELECT SAVINGS EXCESS PLAN

     The Plan named above gives the Employer the right to amend it at any time.
According to that right, the Plan is amended as provided below:

Effective January 1, 2000,

     by striking the following:

          Page 7
          Page 12

     and substituting the following:

          Page 7
          Page 12

     The provisions and conditions set forth on any page of this amendment are a
part of the Plan as fully as if recited over the signature(s) below.

     Unless otherwise stated on any page of this amendment, eligibility for
benefits and the amount of such benefits payable to or on behalf of an
individual who is an inactive Participant on the effective date(s) stated above,
shall be determined according to the provisions of the Plan as in effect on the
day before he became an Inactive Participant.

     By signing this amendment, the Employer acknowledges having counseled to
the extent necessary with selected legal and tax advisors regarding the
amendment's legal and tax implications.

     Signed this 21st day of December 1999.


                                                PRINCIPAL LIFE INSURANCE

                                                By  /s/ MAY F. JOHNSON
                                                    ----------------------------

                                                Vice President - Human Resources
                                                --------------------------------
                                                             Title

<PAGE>   7

                                 AMENDMENT NO. 3

                    THE PRINCIPAL SELECT SAVINGS EXCESS PLAN

     The Plan named above gives the Employer the right to amend it at any time.
According to that right, the Plan is amended as provided below:

Effective January 1, 1998,

     by striking the following:

          Page 3                 Page 8                 Page 16
          Page 6                 Page 9                 Page 20
          Page 7                 Page 14

     and substituting the following:

          Page 3                 Page 8                 Page 16
          Page 6                 Page 9                 Page 16a
          Page 7                 Page 14                Page 20

     by adding the following:

          Page 12a

Effective July 1, 1998,

     by striking the following

          Page 15

     and substituting the following:

          Page 15

     The provisions and conditions set forth on any page of this amendment are a
part of the Plan as fully as if recited over the signature(s) below.

     By signing this amendment, the Employer acknowledges having counseled to
the extent necessary with selected legal and tax advisors regarding the
amendment's legal and tax implications.

     Signed this 1st day of October, 1998.

     PRINCIPAL LIFE INSURANCE COMPANY          PRINCIPAL MUTUAL LIFE INSURANCE
                                               COMPANY

     By /s/ MAY F. JOHNSON                     By /s/ MAY F. JOHNSON
        ------------------------------            ------------------------------

        Vice President-Human Resources            Vice President-Human Resources
        ------------------------------            ------------------------------
                    Title                                      Title


<PAGE>   8


                                 AMENDMENT NO. 2

                    THE PRINCIPAL SELECT SAVINGS EXCESS PLAN

     The Plan named above gives the Employer the right to amend it at any time.
According to that right, the Plan is amended as provided below:

Effective January 1, 1996,

     by striking the following:

          Page 4
          Page 14
          Page 20

     and substituting the following:

          Page 4
          Page 14
          Page 20

Effective July 1, 1997,

     by striking the following:

          Page 12

     and substituting the following:

          Page 12

     The provisions and conditions set forth on any page of this amendment are a
part of the Plan as fully as if recited over the signature(s) below.

     By signing this amendment, the Employer acknowledges having counseled to
the extent necessary with selected legal and tax advisors regarding the
amendment's legal and tax implications.

     Signed this 11th day of September, 1997.

                                            PRINCIPAL MUTUAL LIFE INSURANCE
                                            COMPANY

                                            By  /s/ MAY F. JOHNSON
                                                --------------------------------

                                                Vice President - Human Resources
                                                --------------------------------
                                                             Title

<PAGE>   9

                                 AMENDMENT NO. 1

                    THE PRINCIPAL SELECT SAVINGS EXCESS PLAN

     The Plan named above gives the Employer the right to amend it at any time.
According to that right, the Plan is amended as provided below:

Effective January 1, 1996,

     by striking the following:

          Page 8
          Page 12
          Page 13
          Page 16

     and substituting the following:

          Page 8
          Page 12
          Page 13
          Page 16

     The provisions and conditions set forth on any page of this amendment are a
part of the Plan as fully as if recited over the signature(s) below.

     By signing this amendment, the Employer acknowledges having counseled to
the extent necessary with selected legal and tax advisors regarding the
amendment's legal and tap implications.

     Signed this 21st day of August 1996.

                                              PRINCIPAL MUTUAL LIFE INSURANCE
                                              COMPANY

                                              By /s/ MAY F. JOHNSON
                                                 -------------------------------

                                                            VP-HR
                                              ----------------------------------
                                                            Title


<PAGE>   10

                                  THE PRINCIPAL

                           SELECT SAVINGS EXCESS PLAN


































Nonqualified Retirement Plan 7.5A

Restated January 1, 1994


<PAGE>   11

                          AMEND. NO. 3 PAGE DTD. l-l-98

                                TABLE OF CONTENTS

<TABLE>
<S>                              <C>
INTRODUCTION

ARTICLE I                        DEFINITIONS

ARTICLE II                       PARTICIPATION

       Section 2.01    ----      Excess Plan Active Participant
       Section 2.02    ----      Inactive Participant
       Section 2.03    ----      Cessation of Participation

 ARTICLE Ill                     CONTRIBUTIONS

       Section 3.01    ----      Company Contributions
       Section 3.02    ----      Allocation
       Section 3.03    ----      Transfers

ARTICLE IV                       INVESTMENT OF CONTRIBUTIONS

ARTICLE V                        BENEFITS

      Section 5.01     ----      Retirement Benefits
      Section 5.02     ----      Death Benefits
      Section 5.03     ----      Termination Benefits
      Section 5.04     ----      Disability Benefits

ARTICLE VI                       DISTRIBUTION OF BENEFITS

      Section 6.01     ----      Automatic Forms of Distribution
      Section 6.02     ----      Optional Forms of Distribution
      Section 6.03     ----      Election Procedures
      Section 6.04     ----      Distributions Under Qualified Domestic
                                 Relations Orders

ARTICLE VII                      TERMINATION OF PLAN

ARTICLE VIII                     ADMINISTRATION OF PLAN
</TABLE>


TABLE OF CONTENTS                      3
<PAGE>   12

                          AMEND. NO. 2 PAGE DTD, l-1-96

<TABLE>
<S>                              <C>
ARTICLE IX                       GENERAL PROVISIONS

      Section 9.01     ----      Amendments
      Section 9.02     ----      Provisions Relating to the Insurer
                                 and Other Parties
      Section 9.03     ----      Employment Status
      Section 9.04     ----      Rights to Plan Assets
      Section 9.05     ----      Nonalienation of Benefits
      Section 9.06     ----      Construction
      Section 9.07     ----      Legal Actions
      Section 9.08     ----      Word Usage
      Section 9.09     ----      Small Amounts

PLAN EXECUTION
</TABLE>


TABLE OF CONTENTS                      4
<PAGE>   13


                                  INTRODUCTION

     The Company established the nonqualified Excess Plan on September 1, 1988,
for a select group of management or highly compensated employees who, due to the
amount of their compensation from the Company, are unable to fully participate
in the Elective Deferral and Company Matching Contributions available to the
other eligible participants in the Savings Plan. The Excess Plan has been
designed as, and is intended to be, an unfunded plan for purposes of the
Employee Retirement Income Security Act of 1974, as amended, and a nonqualified
plan for purposes of ss. 401 of the Internal Revenue Code of 1986, as amended.

     The Company is of the opinion that the Excess Plan should be changed. It
believes that the best means to accomplish these changes is to completely
restate the plan's terms, provisions and conditions. The restatement, effective
January 1, 1994, is set forth in this document and is substituted in lieu of
the prior document.

     Any funds accumulated for purposes of providing benefits under this plan
are fully available to satisfy the claims of the Company's creditors.
Participants have no greater rights with regard to such fund than any other
general creditor of the Company.


INTRODUCTION                           5
<PAGE>   14



                                    ARTICLE I

                                   DEFINITIONS

ACCOUNT means, for a Participant, his share of the Investment Fund. Separate
accounting records are kept for those parts of his Account that result from:

(a)  Elective Deferral Contributions.

(b)  Matching Contributions.

(c)  Transfer Account Values

A Participant's Account shall be reduced by any distribution of his Account. A
Participant's Account will participate in the earnings credited, expenses
charged and any appreciation or depreciation of the Investment Fund. His Account
is subject to any minimum guarantees applicable under the Group Contract or
other investment arrangement.

AGENT means an individual who holds an unmodified Agent's Contract and who is
not a General Manager or Management Assistant. On and after August 1, 1998,
Agent also excludes an individual who is acting as a Brokerage General Agent.

AGENT'S CONTRACT means the DD713 contract between the Company and an Agent,
General Manager or Management Assistant. The term Agent's Contract shall also
include any successor full-time agent's contract substituted by the Company
between the Company and such individual and any predecessor full-time agent's
contract which the Company substituted with DO713 or any of its predecessors,

BENEFICIARY means the person or persons named by a Participant to receive any
benefits under this Plan upon the Participant's death. For purposes of this
Plan, Beneficiary is the same as designated by the Participant under the Savings
Plan.

BENEFIT DATE means, for a Participant, the first day of the first period for
which an amount of benefit is payable to him under this Plan. See Article V -
BENEFITS.

BROKERAGE GENERAL AGENT means an individual under the standard compensation plan
who holds an active DD714 Contract or any successor full-time contract with the
Company.

CODE means the Internal Revenue Code of 1986, as amended.

COMPANY means Principal Life Insurance Company (Principal Mutual Life Insurance
Company, before July 1, 1998).

COMPENSATION means the total earnings paid or made available to an Eligible
Employee by the Company during any specified period.

"Earnings" in this definition means earnings as defined in the definition of
Compensation or Earnings in the Savings Plan.


ARTICLE I                              6
<PAGE>   15


Earnings shall also include amounts which are contributed by the Company
according to a salary reduction agreement and which are not currently includable
in the Employee's gross income by reason of the application of Code Sections
125, 402(e)(3), 402(h)(l)(B) or 403(b), as well as Salary Deferral Contributions
under this Plan.

For the purpose of Elective Deferral and Matching Contributions, earnings means
only those amounts in excess of (1) or (2) below, whichever occurs first:

1)   $150,000, as indexed, or

2)   the Compensation determined by the maximum deferral contribution allowed
     under Code Section 402(g) to the Savings Plan divided by the maximum
     deferral percentage allowed by the outcome of the nondiscrimination test
     under the Savings Plan.

CONTRIBUTIONS means

     Elective Deferral Contributions
     Matching Contributions

as set out in Article III, unless the context clearly indicates otherwise.

ELECTIVE DEFERRAL CONTRIBUTIONS means contributions in accordance with a salary
deferral agreement as set out in Article Ill, unless the context clearly
indicates otherwise.

ELIGIBLE EMPLOYEE means any Employee, Agent, General Manager and Management
Assistant.

EMPLOYEE means an individual as defined in the Savings Plan, and will include an
individual employed by an adopting employer, as defined in the Savings Plan.

ENTRY DATE means the date an Eligible Employee first enters the Plan as an
Active Participant. See Article II - PARTICIPATION,

ERISA means the Employee Retirement Income Security Act of 1974, as amended.

EXCESS PLAN means The Principal Select Savings Excess Plan set forth in this
document, including any later amendments to it.

FISCAL YEAR means the Company's taxable year. The last day of the Fiscal Year is
December 31.

GENERAL MANAGER means an individual who is so designated by the Company and who
holds an unmodified Agent's Contract. On and after August 1, 1998, General
Manager excludes an individual who is acting as a Brokerage General Agent.

GROUP CONTRACT means the group annuity contract or contracts into which the
Trustee enters with the Insurer for the investment of Contributions and the
payment of benefits under this Plan. The term Group Contract as it is used in
this Plan is deemed to include the plural unless the context clearly indicates
otherwise.

Any funds accumulated under the Group Contract are available to the general
creditors of the Company.


ARTICLE I                              7
<PAGE>   16


INSURER means Principal Life Insurance Company (Principal Mutual Life Insurance
Company before July 1, 1998), and any other insurance company or companies named
by the Trustee or Company.

INVESTMENT FUND means the total assets held for the purpose of providing
benefits for Participants, These funds result from Contributions made under the
Plan.

The investment Fund is not held for the exclusive benefit of Participants or
their Beneficiaries.

MANAGEMENT ASSISTANT means an individual who is so designated by the Company and
who holds an unmodified Agent's Contract. On and after August 1, 1998,
Management Assistant excludes an individual who is acting as a Brokerage General
Agent.

MATCHING CONTRIBUTIONS means matching contributions as set out in Article III,
unless the context clearly indicates otherwise.

PARTICIPANT means an Eligible Employee who is actively participating in the
Plan.

PAY PERIOD means

(a)  For Agents, General Managers and Management Assistants, Pay Period as
     defined in The Principal Select Savings Plan for Agents, General Managers
     and Management Assistants.

(b)  For all other Employees, Pay Period as defined in The Principal Select
     Savings Plan for Employees.

PLAN ADMINISTRATOR means the person or persons who administer the Plan. The Plan
Administrator is the Company.

PLAN YEAR means a period beginning on a Yearly Date and ending on the day before
the next Yearly Date.

REENTRY DATE means the date a former Participant reenters the Plan. See Article
II - PARTICIPATION.

RETIREMENT DATE means the last day of the month in which a Participant's
Retirement Date occurs under the Savings Plan. This date shall be on or after
the earlier of (i) the date on which he ceases to be an Employee or (ii) the
date he becomes totally and permanently disabled as defined under the Savings
Plan.

SAVINGS PLAN means the qualified plan(s) as follows:

     The Principal Select Savings Plan for Agents, General Managers and
     Management Assistants.

     The Principal Select Savings Plan for Employees.

     TRANSFER ACCOUNT VALUE means for a Participant, the account values, if any,
     which, after a period of five years, automatically transfer to this Plan
     from the Nonqualified Defined Contribution Plan for Designated
     Participants.

     TRUST means an agreement of trust between the Company and Trustee
     established for the purpose of holding and distributing the Trust Fund
     under the provisions of the Excess Plan. The Trust may provide for the
     investment of all or any portion of the Trust Fund in the Group Contract or
     in any mutual fund arrangement available with the Insurer.


ARTICLE I                              8
<PAGE>   17


TRUST FUND means the total funds held under the Trust for the purpose of
providing benefits for Participants. These funds result from Contributions made
under the Excess Plan which are forwarded to the Trustee to be deposited in the
Trust Fund.

TRUSTEE means the trustee or trustees under the Trust. The term Trustee as it is
used in this Plan is deemed to include the plural unless the context clearly
indicates otherwise.

VESTED ACCOUNT means the part of a Participant's Account in which he has a
vested interest. The Participant's Vested Account is equal to his Account.

YEARLY DATE means September 1, 1988, and each following January 1.


ARTICLE I                              9
<PAGE>   18

                                   ARTICLE II

                                  PARTICIPATION

SECTION 2.01--EXCESS PLAN ACTIVE PARTICIPANT.

     A person shall first become a Participant (begin active participation in
the Excess Plan) on the earliest date on or after January 1, 1994, on which the
person is an Eligible Employee and has met the eligibility requirement(s) set
forth below. This date is his Entry Date.

     (1)  He is an active participant in the Savings Plan.

     (2)  He is deferring at least six percent (or the annually determined
          amount, if applicable) into the Savings Plan.

     (3)  He has the required earnings level as provided in the definition of
          Compensation in Article I.

     Each Eligible Employee who was a Participant under the Plan on December 31,
1993, shall continue to be a Participant if he is still an Eligible Employee on
January 1, 1994, and his Entry Date shall not change.

SECTION 2.02--INACTIVE PARTICIPANT.

     An Active Participant shall become an Inactive Participant (discontinue
accruing benefits under the Excess Plan) on the earliest of the following:

     (a)  The effective date of complete termination of the Excess Plan.

     (b)  The date of termination of his agent's contract DD713 (as such
          contract may be amended from time to time, or successor contracts to
          it).

     (c)  The date the Company sends written notice to the Participant of
          cancellation of his agent's contract DD713 (as such contract may be
          amended from time to time, or successor contracts to it).

     (d)  The date the Participant otherwise no longer meets the definition of
          Eligible Employee as set forth in the DEFINITIONS SECTION of Article
          I.

     (e)  The date the Participant no longer meets the terms and conditions set
          forth in the EXCESS PLAN ACTIVE PARTICIPANT SECTION of Article II.

     (f)  The date the Participant revokes his salary deferral agreement.

     A former Participant shall again become a Participant (resume active
participation in the Excess Plan) on the date he again performs an hour of
service as an Eligible Employee. This date is his Reentry Date.


ARTICLE II                             10
<PAGE>   19


SECTION 2.03--CESSATION OF PARTICIPATION.

        A Participant shall cease to be a Participant on the date he is no
longer an Eligible Employee and the value of his Account is zero.


ARTICLE II                             11
<PAGE>   20


                                   ARTICLE III

                                  CONTRIBUTIONS

SECTION 3.01--COMPANY CONTRIBUTIONS.

     Company Contributions for each Plan Year will be equal to the Company
     Contributions as described below.

     (a)  Elective Deferral Contributions. The amount of each Elective Deferral
          Contribution for a Participant shall be equal to any percentage (not
          less than 6% nor more than 8%) of his Compensation for the Pay Period
          as elected in his or her salary deferral agreement. This percentage
          will be adjusted at any time the elective deferral contribution
          percentage under the Savings Plan is increased or decreased. A person
          who is eligible to participate in the Excess Plan may file a salary
          deferral agreement with the Company. The salary deferral agreement to
          start Elective Deferral Contributions may be effective on a
          Participant's Entry Date (Reentry Date, if applicable) or any
          following date. The Participant shall make any change or terminate the
          salary deferral agreement by filing a new salary deferral agreement. A
          Participant's salary deferral agreement making a change may be
          effective on any date a salary deferral agreement to start Elective
          Deferral Contributions could be effective. A Participant's salary
          deferral agreement to stop Elective Deferral Contributions may be
          effective on any date.

          The salary deferral agreement must be effective before the beginning
          of the Pay Period in which Elective Deferral Contributions are to
          start or stop.

          Elective Deferral Contributions may include contributions the person
          would have made to the Savings Plan under its contribution formula but
          for the additional restrictions imposed by such plan to meet the
          qualification requirements of the Internal Revenue Code.

     (b)  Matching Contributions. The amount of each Matching Contribution made
          by the Company for a Participant shall be equal to 50% of the
          Participant's Elective Deferral Contributions for the Pay Period. The
          amount of Matching Contribution made by the Company for a Participant
          shall not exceed three percent of his Compensation for the Pay Period.

          Matching Contributions may include contributions the Company would
          have made to the Savings Plan under its contribution formula but for
          the additional restrictions imposed by such plan to meet the
          qualification requirements of the Internal Revenue Code.

SECTION 3.02--ALLOCATION.

     The following Contributions for each Plan Year shall be allocated to each
Participant for whom such Contributions were made under the COMPANY
CONTRIBUTIONS SECTION of Article III:

     Elective Deferral Contributions
     Matching  Contributions

These Contributions shall be allocated when made and credited to the
Participant's Account.


ARTICLE III                            12
<PAGE>   21


SECTION 3.03--TRANSFERS.

     Each Plan Year, Contributions made on behalf of a Participant due to his
participation in the Nonqualified Defined Contribution Plan for Designated
Participants may be automatically transferred from such other nonqualified plan
to this Plan. Any such transfer shall occur on or after the date which is five
years after the contribution was made to such other nonqualified plan.

     These contributions are allocated to the Participant upon transfer to this
Plan. This is his Transfer Account Value.


ARTICLE III                           12a
<PAGE>   22


                                   ARTICLE IV

                          INVESTMENT OF CONTRIBUTIONS

     Contributions made under the Excess Plan shall be deposited with the
Trustee to be invested in the Trust Fund. Investment of such Contributions will
be in accordance with the provisions of the Trust which will include, but not be
limited to, investments under the provisions of any applicable group contract or
any mutual fund I arrangement with the Insurer. The amounts in the Trust are
subject to the claims of the Company's creditors, in the event of the Company's
insolvency.

     To the extent permitted by the Trust, the Participant shall direct the
Contributions to any of the investments available under the Trust. If no
investment direction is given, Contributions will be invested according to the
provisions of any applicable group contract. (A change in investment direction
or a transfer to) or from an account of a Participant may be made at any time,
according to such terms and conditions as the Trustee may specify and subject to
the provisions of the investments available under the Trust.


ARTICLE IV                             13
<PAGE>   23


                                    ARTICLE V

                                    BENEFITS

SECTION 5.01--RETIREMENT BENEFITS.

     On a Participant's Retirement Date, his Vested Account shall be distributed
to him according to the distribution of benefits provisions of Article VI. I

SECTION 5.02--DEATH BENEFITS.

     If a Participant dies before his Retirement Date, his Vested Account shall
be distributed according to the distribution of benefits provisions of Article
VI and the SMALL AMOUNTS SECTION of Article IX.

SECTION 5.03--TERMINATION BENEFITS.

     A Participant will receive a distribution of his Vested Account if he
ceases to be an Eligible Employee before his Retirement Date, provided he has
not again become an Eligible Employee.

SECTION 5.04--DISABILITY BENEFITS.

     If a Participant becomes totally and permanently disabled, as defined in
the Associated Plan, his Vested Account shall be distributed to him in a single
sum payment. Such payment shall be made after the Participant has been totally
and permanently disabled for one year.


ARTICLE V                              14
<PAGE>   24


                                   ARTICLE VI

                            DISTRIBUTION OF BENEFITS

SECTION 6.01--AUTOMATIC FORMS OF DISTRIBUTION.

     The automatic form of benefit payable to or on behalf of a Participant is
determined as follows:

     (a)  The automatic form of retirement benefit shall be a single sum
          payment.

     (b)  The automatic form of death, disability and termination benefit shall
          be a single sum payment to the Participant or his Beneficiary.

SECTION 6.02--OPTIONAL FORMS OF DISTRIBUTION.

     An election of an optional form of benefit may be made by the Participant
(see the ELECTION PROCEDURES SECTION of Article VI).

     (a)  The optional forms of retirement benefit shall be the following:
          single life annuity with a certain period of ten years; a single life
          annuity with installment refund; survivorship life annuity with
          installment refund and a survivorship percentage of 50; and fixed
          period annuities for any period of whole months which is not less than
          120 and does not exceed the life expectancy of the Participant and the
          named Beneficiary.

          The following optional forms of retirement benefit are also available:
          a single sum payment; an annual distribution equal to any fixed whole
          percentage, not less than 10% and not more than 13%, as elected by the
          Participant, of his Vested Account. Such amount shall be payable
          annually until his Vested Account is exhausted. Once elected, the
          percentage will not change, An election under this paragraph may be
          delayed until the Participant reaches his required beginning date
          under the Associated Plan.

     If the Participant dies before beginning to receive a distribution of his
     retirement benefits, any form of distribution for a death benefit must meet
     the following limitations:

     (b)  If the Participant did not name an individual as his Beneficiary to
          receive any death benefit payable under the DEATH BENEFITS SECTION of
          Article V, such death benefit shall be distributed within five years
          of the Participant's death.


ARTICLE VI                             15
<PAGE>   25


          A form of distribution for retirement or death benefits shall be
          available to a Participant or Beneficiary only if the annual
          distribution under such form is at least equal to the quotient of the
          Participant's Vested Account as of the date distribution is to begin,
          divided by the life expectancy of the Participant, Beneficiary or
          joint and last survivor expectancy of the Participant and Beneficiary,
          as appropriate. If distribution is in a form other than a life
          annuity, the life expectancy of the Participant (and/or Beneficiary,
          if the spouse is the Beneficiary) may be recalculated after
          distribution begins, but no more frequently than annually. In the case
          of a Beneficiary who is not the Participant's spouse, life expectancy
          shall be calculated when benefits start and minimum payments for any
          12-consecutive month period will be based on such life expectancy
          minus the number of whole years since the distribution first began.
          The life expectancy or joint and last survivor expectancy shall be
          computed by use of the return multiplies contained in Section 1.72-9
          of the regulations under the Code.

SECTION 6.03--ELECTION PROCEDURES.

     The Participant or Beneficiary shall make any election under this section
in the form or manner provided for that purpose. The Plan Administrator may
require such individual to complete any necessary documents as to the provisions
to be made. Effective July 1, 1998, any election made as to a Participant whose
Retirement Date occurs on and after January 1, 1999, must be made no later than
the date one-year prior to his Retirement Date. In the absence of such election,
benefits shall be paid in a single sum payment.

     (a)  Retirement Benefits. A Participant may elect his Beneficiary and may
          elect to have retirement benefits distributed under any of the
          optional forms of retirement benefit described in the OPTIONAL FORMS
          OF DISTRIBUTION SECTION of Article VI.

     (b)  Death Benefits. A Participant may elect his Beneficiary and may elect
          to have death benefits distributed under any of the optional forms of
          death benefit described in the OPTIONAL FORMS OF DISTRIBUTION SECTION
          of Article VI.

          If the Participant has not elected an optional form of distribution
          for the death benefit payable to his Beneficiary, the Beneficiary may,
          for his own benefit, elect the form of distribution, in like manner as
          a Participant.

SECTION 6.04--DISTRIBUTIONS UNDER QUALIFIED DOMESTIC RELATIONS ORDERS.

     The Plan specifically permits distributions to an alternate payee under a
qualified domestic relations order, as defined in Code Section 414(p), at any
time, irrespective of whether the Participant has attained his earliest
retirement age, as defined in Code Section 414(p), under the Plan. A
distribution to an alternate payee before the Participant's attainment of
earliest retirement age, as defined in Code Section 414(p), is available only
if:

     (a)  the order specifies distributions at that time or permits an agreement
          between the Plan and the alternate payee to authorize an earlier
          distribution; and

     (b)  if the present value of the alternate payee's benefits under the Plan
          exceeds $5,000, and the order requires, the alternate payee consents
          to any distribution occurring before the Participant's attainment of
          earliest retirement age, as defined in Code Section 414(p).

Nothing in this section shall permit a Participant a right to receive a
distribution at a time otherwise not permitted under the Plan nor shall it
permit the alternate payee to receive a form of payment not permitted under the
Plan.


ARTICLE VI                             16
<PAGE>   26


     The Plan Administrator shall establish reasonable procedures to determine
the qualified status of a domestic relations order. Upon receiving a domestic
relations order, the Plan Administrator promptly shall notify the Participant
and an alternate payee named in the order, in writing, of the receipt of the
order and the Plan's procedures for determining the qualified status of the
order. Within a reasonable period of time after receiving the domestic relations
order, the Plan Administrator shall determine the qualified status of the order
and shall notify the Participant and each alternate payee, in writing, of its
determination. The Plan Administrator shall provide notice under this paragraph
by mailing to the individual's address specified in the domestic relations
order, or in a manner consistent with Department of Labor regulations. The Plan
Administrator may treat as qualified any domestic relations order entered before
January 1, 1985, irrespective of whether it satisfies all the requirements
described in Code Section 414(p).

     If any portion of the Participant's Account is payable during the period
the Plan Administrator is making its determination of the qualified status of
the domestic relations order, a separate accounting shall be made of the amount
payable. If the Plan Administrator determines the order is a qualified domestic
relations order within 18 months of the date amounts are first payable following
receipt of the order, the payable amounts shall be distributed in accordance
with the order, If the Plan Administrator does not make its determination of the
qualified status of the order within the 4 8 month determination period, the
payable amounts shall be distributed in the manner the Plan would distribute if
the order did not exist and the order shall apply prospectively if the Plan
Administrator later determines the order is a qualified domestic relations
order.

     The Plan shall make payments or distributions required under this section
by separate benefit checks or other separate distribution to the alternate
payee(s).


ARTICLE VI                            16a
<PAGE>   27

                                  ARTICLE VII

                               TERMINATION OF PLAN

     The Company expects to continue the Plan indefinitely but reserves the
right to terminate the Plan at any time upon giving written notice to all
parties concerned. Complete discontinuance of Contributions under the Plan
constitutes termination of the Plan.

     The Participant's Account shall continue to participate in the investment
earnings credited, expenses charged and any appreciation or depreciation of the
Investment Fund until the Account is distributed.

     A Participant's Account may be distributed to the Participant after the
effective date of the Plan termination.

     Upon termination of the Plan, no more Eligible Employees shall become
Participants and no more Contributions shall be made.

     Amounts in this Plan shall not be paid to the Company at any time, except
that, after the satisfaction of all liabilities under the Plan, any amounts
remaining may be paid to the Company. The payment may not be made if it would
contravene any provision of law.


ARTICLE VII                            17
<PAGE>   28


                                  ARTICLE VIII

                             ADMINISTRATION OF PLAN

       The administrative provisions contained in Article VIII of the Savings
Plan, except for Section 8.07, are hereby incorporated by reference into this
Plan.




ARTICLE VIII                           18
<PAGE>   29

                                   ARTICLE IX

                             GENERAL PROVISIONS

SECTION 9.01--AMENDMENTS.

     By resolution of its Management Resources Committee, the Company may amend
this Excess Plan at any time, including any remedial retroactive changes (within
the specified period of time as may be determined by Internal Revenue Service
regulations) to comply with the requirements of any law or regulation issued by
any governmental agency to which the Company is subject.

     Effective August 15, 1994, the Management Resources Committee is the
Corporate Management Committee.

SECTION 9.02--PROVISIONS RELATING TO THE INSURER AND OTHER PARTIES.

     The obligations of an Insurer shall be governed solely by the provisions of
the Group Contract. The Insurer shall not be required to perform any act not
provided in or contrary to the provisions of the Group Contract. See the
CONSTRUCTION SECTION of this article.

     Any issuer or distributor of investment contracts or securities is governed
solely by the terms of its policies, written investment contract, prospectuses,
security instruments, and any other written agreements entered into with the
Trustee.

     Such Insurer, issuer or distributor is not a party to the Excess Plan, nor
bound in any way by the Excess Plan provisions. Such parties shall not be
required to look to the terms of this Excess Plan, nor to determine whether the
Company, the Plan Administrator or the Trustee have the authority to act in any
particular manner or to make any contract or agreement.

     Until notice of any amendment or termination of this Excess Plan or a
change in Trustee has been received by the Insurer at its home office or an
issuer or distributor at their principal address, they are and shall be fully
protected in assuming that the Excess Plan has not been amended or terminated
and in dealing with any party acting as Trustee according to the latest
information which they have received at their home office or principal address.

SECTION 9.03.--EMPLOYMENT STATUS.

     Nothing contained in this Excess Plan gives an Eligible Employee the right
to be retained in the Company's employ or to interfere with the Company's right
to discharge any Eligible Employee.

SECTION 9.04-RIGHTS TO PLAN ASSETS.

     No Eligible Employee shall have any right to or interest in any assets of
the Excess Plan upon termination of his employment or otherwise except as
specifically provided under this Excess Plan, and then only to the extent of the
benefits payable to such Eligible Employee in accordance with the Excess Plan
provisions.


ARTICLE IX                             19
<PAGE>   30


     Any final payment or distribution to a Participant or his legal
representative or to any Beneficiaries or spouse of such Participant under the
Excess Plan provisions shall be in full satisfaction of all claims against the
Excess Plan, the Plan Administrator, the Trustee, the Insurer, and the Company
arising under or by virtue of the Excess Plan.

SECTION 9.05--NONALIENATION OF BENEFITS.

     Benefits payable under the Excess Plan are not subject to the claims of any
creditor of any Participant, Beneficiary or spouse. A Participant, Beneficiary
or spouse does not have any rights to alienate, anticipate, commute, pledge,
encumber or assign any of such benefits. The preceding sentences shall also
apply to the creation, assignment, or recognition of a right to any benefit
payable with respect to a Participant according to a domestic relations order,
unless such order is determined by the Plan Administrator to be a qualified
domestic relations order, as defined in ERISA Act Section 206(d), or any
domestic relations order entered before January 1, 1985.

SECTION 9.06--CONSTRUCTION.

     The validity of the Excess Plan or any of its provisions is determined
under and construed according to Federal law and, to the extent permissible,
according to the laws of the state in which the Company has its principal
office. In case any provision of this Excess Plan is held illegal or invalid for
any reason, such determination shall not affect the remaining provisions of this
Excess Plan, and the Excess Plan shall be construed and enforced as if the
illegal or invalid provision had never been included.

     In the event of any conflict between the provisions of the Excess Plan and
the terms of any contract or policy issued hereunder, the provisions of the
Excess Plan control the operation and administration of the Excess Plan.

SECTION 9.07--LEGAL ACTIONS.

     The Plan, the Plan Administrator and the Trustee are the necessary parties
to any action or proceeding involving the assets held with respect to the Plan
or administration of the Plan or Trust. No person employed by the Company, no
Participant, former Participant or their Beneficiaries or any other person
having or claiming to have an interest in the Plan is entitled to any notice of
process. A final judgment entered in any such action or proceeding shall be
binding and conclusive on all persons having or claiming to have an interest in
the Plan.

SECTION 9.08--WORD USAGE.

     The masculine gender, where used in this Plan, shall include the feminine
gender and the singular words as used in this Plan may include the plural,
unless the context indicates otherwise.

SECTION 9.09--SMALL AMOUNTS.

     If the Vested Account of a Participant does not exceed $5,000, the entire
Vested Account shall be payable in a single sum as of the earliest of his
Retirement Date, the date he dies, or the date he ceases to be an Employee. This
is a small amounts payment. If a small amount is payable as of the date the
Participant dies, the small amounts payment shall be made to the Participant's
Beneficiary. If a small amount is payable while the Participant is living, the
small amounts payment shall be made to the Participant. The small amounts
payment is in full settlement of all benefits otherwise payable.

     No other small amounts payments shall be made.


ARTICLE IX                             20
<PAGE>   31
     By executing this Plan, the Company acknowledges having counseled to the
extent necessary with selected legal and tax advisors regarding the Plan's
legal and tax implications.

     Executed this 6th day of November, 1995.
                   ---        --------    --

                                    PRINCIPAL MUTUAL LIFE INSURANCE COMPANY

                                    By: /s/ THOMAS J. GAARD
                                        -----------------------------------

                                        Sr. Vice President
                                        -----------------------------------
                                                       Title







PLAN EXECUTION                         21
<PAGE>   32
              AMENDMENT TO THE PRINCIPAL SELECT SAVINGS EXCESS PLAN

                                       AND

     THE NONQUALIFIED DEFINED CONTRIBUTION PLAN FOR DESIGNATED PARTICIPANTS

                    (Hereinafter referred to as the "Plans")

The Plans named above give the Company the right to amend them at any time.

WHEREAS, in furtherance of the proposed demutualization of Principal Mutual
Holding Company, the Board of Directors of Principal Mutual Holding Company, on
March 3 1,2001, adopted a Plan of Conversion which contains certain provisions
applicable to the above plans, collectively defined as the "Excess Plans" in
such Plan of Conversion; and

WHEREAS, in order to reflect the provisions of Section 8.1 of the Plan of
Conversion as they relate to the above Plans, the following definitions are
adopted for purposes of this Amendment which relates specifically to provisions
and limitations reflected in Section 8.1 of the Plan of Conversion and for no
other purpose.

NOW THEREFORE, effective as of the effective date of the Plan of Conversion of
Principal Mutual Holding Company, the Plans are hereby amended as follows:

By adding the following definitions, in correct alphabetical order, to Article I
of such Plans:

     "Agents Savings Plan" means The Principal Select Savings Plan for
     Individual Field.

     "Common Stock" means the common stock, par value $0.01 per share, of the
     Principal Financial Group, Inc., a Delaware corporation, and any successor
     thereto.

     "Company Stock Plan" means any stock option plan, stock incentive plan,
     stock purchase plan and share ownership plans related to the Common Stock
     that are customary for publicly traded companies, and shall include the
     Directors Stock Plan, the Long-Term Plan, the Plan, the Savings Plans, the
     Stock Incentive Plan and the Stock Purchase Plan.

     "Directors Stock Plan" means the Principal Financial Group, Inc. Directors
     Stock Plan.

     "Employees Savings Plan" means The Principal Select Savings Plan for
     Employees.

     "Excess Plan" for purposes of the Amendment to the Principal Select Savings
     Excess Plan and the Non-Qualified Defined Contribution Plan for Designated
     Participants relating to the Plan of Conversion, adopted as of May 21,2001,
     means the Principal Select Savings Excess Plan and the Non-Qualified
     Defined Contribution Plan for Designated Participants.

     "Long-Term Plan" means the Principal Financial Group Long-Term Performance
     Plan.

     "Plan of Conversion" means the Plan of Conversion of Principal Mutual
     Holding Company.


<PAGE>   33

     "Plans" for purposes of the Amendment to the Principal Select Savings
     Excess Plan and the Non- Qualified Defined Contribution Plan for Designated
     Participants relating to the Plan of Conversion, adopted as of May 21,2001,
     means the Principal Select Savings Excess Plan and the Non-Qualified
     Defined Contribution Plan for Designated Participants.

     "Savings Plans" for purposes of the Amendment to the Principal Select
     Savings Excess Plan and the Non-Qualified Defined Contribution Plan for
     Designated Participants relating to the Plan of Conversion, adopted as of
     May 2 1,2001, means the Employees Savings Plan, the Agents Savings Plan and
     the Excess Plan.

     "Stock Incentive Plan" means the Principal Financial Group, Inc. Stock
     Incentive Plan.

     "Stock Purchase Plan" means the Principal Financial Group, Inc. Employee
     Stock Purchase Plan.

By adding a new Section 9.09 to Article IX, to read as follows:

     Section 9.09. -- Limitations.

     Notwithstanding anything else contained in the Plans to the contrary, no
     action shall be taken, and no award or distribution shall be made, under
     the Plans, which contains any term or condition that would violate any
     provision of the Plan of Conversion. To the extent that shares of Common
     Stock are made available for distribution hereunder, the number of such
     shares distributed hereunder shall count against (i) the limit of 6% of the
     number of shares of Corm-non Stock outstanding immediately following the
     effective date of the Plan of Conversion that may be made issuable or
     distributable under all Company Stock Plans (including, without limitation,
     the Plans) other than the Employees Savings Plan, the Agents Savings Plan
     and the Stock Purchase Plan, and (ii) the guideline set forth in the Stock
     Incentive Plan limiting the maximum number of shares of Common Stock that
     may be awarded or issued within 18 months of the effective date of the Plan
     of Conversion to 40% of the limit set forth in subclause (i).

By signing this amendment, the Company, as plan sponsor, has made the decision
to adopt this plan amendment as of May 21, 2001.

Signed this    21    day of           May          , 2001.
            --------        -----------------------


                                        PRINCIPAL LIFE INSURANCE COMPANY

                                        By: /s/ Jim DeVries
                                            ------------------------

                                        Title: Vice President -- HR
                                            ------------------------

                                       2