<PAGE>   1
                                  EXHIBIT 99.7

                         SUPPLEMENTAL BENEFIT AGREEMENT

         THIS SUPPLEMENTAL  BENEFIT  AGREEMENT (this  "Agreement") is entered
into and made effective as of the 7th day of February, 2000, by and between
           , an individual residing at                 ("Employee"), and AmerUs
Life Insurance Co., an Iowa corporation having its principal place of business
at 611 5th Avenue, Des Moines, Iowa  50309 ("Employer").

         WHEREAS, Employer currently employs Employee                         of
Employer; and

         WHEREAS, Employer and Employee wish to enter into an agreement
concerning a certain aspect of their employment relationship;

         NOW, THEREFORE, in consideration of the mutual promises and covenants
contained in this Agreement and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties agree as
follows:

         Section 1. Definitions. Whenever used herein, capitalized words and
phrases, unless the context otherwise requires, shall have the meanings ascribed
in the text, or as set forth on Exhibit A, which is attached hereto and made a
part hereof.

         Section 2. Termination of Employment by Employee for Good Reason.

                  a. If the employment of Employee is terminated by Employee for
Good Reason, Employee shall be entitled to the Severance Payment and the
Continued Benefits.

                  b. Any offer of Comparable Employment following a Change of
Control shall remain open for at least fifteen (15) days after such offer is
extended to Employee. If Employee does not accept an offer of Comparable
Employment following a Change of Control within fifteen (15) days after it is
offered, all rights of Employee under this Agreement shall cease.

                   c. If Employee timely accepts an offer of Comparable
Employment following a Change of Control and if within two (2) years following
the date such offer of Comparable Employment is accepted either (i) the
employment of Employee is terminated by Employer without Cause (as such term is
described in Section 4 hereof) or (ii) a Material Event occurs and Employee
elects to terminate his or her employment with Employer (which will also be
considered a termination of employment by Employee for Good Reason for purposes
hereof), then Employee shall be entitled to the Severance Payment and the
Continued Benefits.

         Section 3. Termination of Employment by Employer Following Change of
Control. If the employment of Employee is terminated by Employer following a
Change of Control, and such termination is not for Cause as described in Section
4 hereof, Employee shall be entitled to the Severance Payment and the Continued
Benefits; provided, however, that if the Employee accepts an offer of Comparable
Employment, the provisions of Section 2(c) shall apply rather than this Section
3.



<PAGE>   2

         Section 4. Termination of Employment by Employer for Cause. Employer
may terminate the employment of Employee at any time for Cause. Employer shall
have "Cause" to terminate Employee's employment for Employee's personal
dishonesty, gross negligence, willful misconduct, breach of fiduciary duty
involving personal profit, intentional failure to perform stated duties, or
willful violation of any law, rule, regulation (other than traffic violations or
similar offenses) or final cease-and-desist order. Upon termination for Cause,
all rights of Employee under this Agreement shall cease as of the Termination
Date.

         Section 5. Notice of Termination. Any termination of the employment of
Employee shall be communicated by a Notice of Termination to the other party
hereto. If there is any dispute or controversy under this Agreement with respect
to Employee's entitlement to the Severance Payment or Continued Benefits, or the
amount of same, except in the event of a termination for Cause by Employer,
Employer shall continue to pay Employee the full compensation and benefits in
effect when the Notice of Termination was given (including without limitation
Base Compensation and payments under any bonus and incentive plans in which
Employee participates), until the earlier of the date when the dispute is
finally resolved or twelve (12) months from the date when the Notice of
Termination was given. Amounts paid under the preceding sentence shall be offset
against and shall reduce any other amounts due under this Agreement, including
any Severance Payment or Continued Benefits and any arbitration award under
Section 11 hereof.

         Section 6. Severance Payment. In the event the employment of Employee
is terminated by Employee for Good Reason as described in Section 2 hereof or by
Employer following a Change of Control as described in Section 3 hereof,
Employer shall pay to Employee the following Severance Payment, which shall be
paid in a lump sum within thirty-five (35) days following the Termination Date:

                  a.       Any amount of Employee's Base Compensation earned but
unpaid through the  Termination Date; and

                  b. In lieu of any further salary or other payments of any kind
to Employee for periods after the Termination Date, an amount equal to:

                           i.      the sum of:

                                   (1)      Employee's Base Compensation, plus

                                   (2)      the amount of Employee's annual
                                            bonus that would have been paid
                                            immediately preceding the
                                            Termination Date assuming the Plan
                                            Target Level (as defined by the
                                            Plan) had been achieved;

                           ii.     multiplied by the number two(2); and

                  c. An amount equal to the contributions from the Employer the
Employee would have otherwise been entitled to under the Plans if Employee had
remained an employee of Employer


                                       3
<PAGE>   3

until and including December 31 of the calendar year in which Employee's
employment terminates and Employee had earned the amounts set forth in Section
6.b.i above through said December 31st; provided, however, if Section 280G(a) of
the Internal Revenue Code of 1986, as amended (the "Code"), is applicable, the
amount of Severance Payment described herein shall be limited to the extent
necessary so that, within the meaning of Section 280G(b)(2)(A)(ii) of the Code,
the aggregate present value of the payments in the nature of compensation to (or
for the benefit of) the Employee which are contingent on a Change of Control
(with a Change of Control for this purpose being defined in terms of a "change"
described in either Section 280G(b)(2)(A)(i)(I) or (II) of the Code) are limited
to an amount equal to 2.999 multiplied by the "base amount," as such term is
defined in Section 280G(b)(3) of the Code.

         Section 7. Continued Benefits. In the event the employment of Employee
is terminated by Employee for Good Reason as described in Section 2 hereof or by
Employer following a Change of Control as described in Section 3 hereof,
Employer shall continue to provide to Employee the Continued Benefits described
in this Section 7. Employer shall maintain in full force and effect, for the
benefit of Employee for two (2) years after the Termination Date, all employee
welfare benefit plans and programs or arrangements in which Employee was
entitled to participate immediately prior to the Termination Date (the
"Continued Benefits"); provided, however, that Employee's continued
participation is possible under the general terms and provisions of such plans,
programs and arrangements. In the event that Employee's continued participation
in any such plan, program or arrangement is not possible, Employer shall arrange
to provide Employee with substantially equivalent benefits. At the end of the
period of coverage, Employee shall have the option to have assigned to Employee
at no cost and with no apportionment of prepaid premiums any assignable
insurance policy owned by Employer and relating specifically to Employee.
Notwithstanding the foregoing, Employee's period of continued coverage under any
such plan, program or arrangement (or any Employer-arranged provision of such
benefits) shall terminate as of the date Employee becomes eligible to
participate in a similar plan, program or arrangement of another employer.
Employee shall be deemed to be "eligible to participate" for this purpose even
if Employee is required to pay an employee premium and even if the new plan,
program or arrangement imposes preexisting condition limitations or
restrictions. In addition, Employee shall be fully vested in all of his or her
account in the AllHAAmerUs Savings & Retirement Plan and the AllHAAmerUs
Supplemental Executive Retirement Plan.

         Section 8. No Mitigation. Employee shall not be required to mitigate
the amount of any Severance Payment or Continued Benefits by seeking other
employment or otherwise, nor shall the amount of any Severance Payment or
Continued Benefits (other than the earlier termination of certain employee
benefits as described in Section 7 hereof) be reduced by any compensation earned
by Employee as a result of employment by another employer after termination of
this Agreement or otherwise. Employer's obligation to pay Employee the
compensation and make the arrangements provided herein shall be absolute and
unconditional and, following any Change of Control, shall not be affected by any
circumstances, including without limitation any set-off (except as provided in
Sections 5 and 9.b. hereof), counterclaim, recoupment, defense or other rights
which Employer may have. Except as otherwise provided herein, all amounts
payable by Employer shall be paid without notice or demand.


                                       4
<PAGE>   4


         Section 9.      Indemnification.

                  a.     Employer shall pay, and indemnify Employee against, all
costs and expenses, including without limitation the fees and expenses of
attorneys, arbitrators, experts and witnesses, incurred by or on behalf of
Employee in connection with any arbitration or legal claim or proceeding arising
from this Agreement or the interpretation thereof, to the extent that Employee
is successful, on the merits or otherwise, in any such claim or proceeding. If
Employee is not wholly successful in such claim or proceeding but is successful,
on the merits or otherwise, as to one or more but less than all claims, issues
or matters in such claim or proceeding, then Employer shall indemnify Employee
against all such costs and expenses incurred by Employee or on Employee's behalf
in connection with each successfully resolved claim, issue or matter.

                  b.     Employer shall advance all such costs and expenses
incurred by or on behalf of Employee in connection with any such claim or
proceeding referred to in Section 9.a. hereof within twenty (20) days after
receipt by Employer of a statement or statements from Employee requesting such
advance or advances, whether prior to or after final disposition of such claim
or proceeding. Such statement or statements shall reasonably evidence the costs
and expenses incurred by Employee and shall be preceded or accompanied by an
undertaking by or on behalf of Employee to repay any costs and expenses advanced
if it shall ultimately be determined that Employee is not entitled to be
indemnified against such costs and expenses and, furthermore, if Employee fails
to repay any costs and expenses that are advanced, then such amounts shall be
offset against and shall reduce any other amounts due to Employee under this
Agreement.

         Section 10.     Notices. All notices and other communications provided
for or permitted hereunder shall be made in writing by hand delivery, registered
first-class mail, telecopier or commercial courier guaranteeing next day
delivery to the respective addresses provided for Employer and Employee in the
introductory paragraph of this Agreement. Notices to Employer shall be addressed
to the attention of the Chief Executive Officer and the Corporate Secretary of
Employer. All such notices and communications shall be deemed to have been duly
given; at the time delivered by hand, if personally delivered; five (5) business
days after being deposited in the mail, postage prepaid, if mailed; when receipt
is acknowledged, if telecopied; and the next business day after timely delivery
to the courier, if sent by commercial courier guaranteeing next day delivery.

         Section 11.     Arbitration. Employer and Employee agree that any
disputes arising out of or relating to this Agreement shall be arbitrated in
accordance with the rules of the American Arbitration Association and the
Federal Arbitration Act. Such arbitration shall be held in Des Moines, Iowa. No
party shall initiate arbitration unless, at least thirty (30) days prior
thereto, such party has given the other party written notice of the intent to
initiate arbitration and a detailed description of the basis of the dispute. A
single arbitrator (or, in any matter in which the amount in controversy exceeds
$500,000, a panel of three (3) arbitrators) shall interpret this Agreement in
accordance with Iowa laws and shall conduct proceedings in accordance with the
Federal Rules of Civil Procedure. Punitive damages, if any, awarded by the
arbitrator(s) shall not exceed two (2) times compensatory damages awarded. Any
award of the arbitrator(s) shall be deemed final, and judgment upon such award
may be entered and enforced in any Iowa District Court and transferred to any
other jurisdiction.

                                       5

<PAGE>   5

         Section 12.     Tax Withholding. Employer shall have the right to
withhold from any transfer or payment made to Employee or to any other Person
hereunder, whether such payment is to be made in cash or other property, all
applicable federal, state, city or other taxes or foreign taxes as shall be
required in the determination of Employer pursuant to any statute or
governmental regulation or ruling.

         Section 13.     Interest. Employer shall pay Employee interest at a
rate of ten percent (10%) per annum on any benefits payable to Employee
hereunder not paid by the date provided for herein from such date until the date
of payment.

         Section 14.     General Creditor. Nothing contained in this Agreement
and no action taken pursuant to the provisions of this Agreement shall create or
be construed to create a trust of any kind or a fiduciary relationship between
Employer and Employee or any other Person, nor shall any money or property of
Employer be segregated for the benefit of Employee to satisfy the obligations of
Employer hereunder. To the extent that Employee acquires a right to receive
payments hereunder, such rights shall be no greater than the right of any
general unsecured creditor of Employer. Except as expressly provided herein,
each payment shall be made in cash from the general assets of Employer.

         Section 15.     No Waiver. The failure of either party to require the
performance of any term or condition of this Agreement, or the waiver by either
party of any breach of this Agreement, shall not prevent a subsequent
enforcement of any term or condition nor be deemed to be a waiver of any
subsequent breach by either party.

         Section 16.     Binding Effect. This Agreement shall be binding on and
inure to the benefit of the successors and assigns of Employer. This Agreement
shall inure to the benefit of and be enforceable by Employee's personal or legal
representatives, executors, administrators, successors, heirs, distributees,
devisees and legatees.

         Section 17.     No Assignment. The right of Employee or any other
Person to the payment of amounts or other benefits under this Agreement shall
not be assigned, alienated, hypothecated, placed in trust, disposed of,
transferred, pledged or encumbered (except as provided in Section 16 herein)
and, to the extent permitted by law, no such amount or payment shall in any way
be subject to any legal process to subject the same to the payments of any claim
against Employee or any other Person.

         Section  18.    Paragraphs and Other Headings.  The paragraph headings
contained in this Agreement are for reference purposes only and shall not affect
the interpretation of this Agreement.

         Section  19.    Governing  Law.  This Agreement and all transactions
contemplated by this Agreement shall be governed by, and construed and enforced
in accordance with, the laws of the State of Iowa, without regard to principles
of conflicts of laws.

         Section 20.     Severability. If any one or more of the provisions
contained in this Agreement shall for any reason be held invalid, illegal or
unenforceable, such invalidity, illegality or unenforceability shall not affect
any other provisions of this Agreement, which shall be construed as

                                       6

<PAGE>   6

if such invalid, illegal or unenforceable provision had never been contained
herein. It is the intention of the parties that if any provision of this
Agreement is capable of two constructions, one of which would render the
provision void and the other of which would render the provision valid, then the
provision shall have the meaning that renders it valid.

         Section 21.     At-Will Employment. Nothing in this Agreement shall
alter the "at-will" nature of Employee's employment with Employer, it being
understood that the "at-will" nature of Employee's employment with Employer
shall in no way alter the benefits to which Employee is otherwise entitled under
this Agreement.

         Section 22.     Survivability.  The obligations of Employer and
Employee under this Agreement shall survive the termination of this Agreement.

         Section 23.     Employer After A Change of Control. Following a Change
of Control and the acceptance by Employee of an offer of Comparable Employment,
the term "Employer" shall be deemed to mean the actual employer of Employee
(which may be Employer, an affiliate thereof or some other Person involved in
the Change of Control).

         Section 24.     Entire Agreement. This Agreement sets forth the entire
understanding of the parties and supersedes all other representations,
agreements and understandings, oral or otherwise, between or among the parties
with respect to the matters contained herein.

         IN WITNESS WHEREOF, the parties have set their respective signatures as
of the day and year first above written.

<TABLE>
<CAPTION>
EMPLOYEE                                    AMERUS LIFE INSURANCE COMPANY
<S>                                         <C>

By:                                         By:
   ----------------------------------          ------------------------------
Print Name:                                 Its:
           --------------------------           -----------------------------
</TABLE>

                                       7

<PAGE>   7



                                    EXHIBIT A

                                   DEFINITIONS


         "Affiliate" shall mean with respect to any Person, any Person which,
directly or indirectly, through one or more intermediaries, controls, is
controlled by or is under common control with such entity; provided, however,
that any Person which owns directly or indirectly ten percent (10%) or more of
the securities having ordinary voting power for the election of directors or any
other governing body of a corporation or ten percent (10%) or more of the
partnership or other ownership interests of any other Person (other than as a
limited partner of such Person) will be deemed to control such Person.

         "AMHC" shall mean American Mutual Holding Company.

         "Base Compensation" shall mean the greater of (i) the semi-monthly
salary paid to Employee by Employer which was in effect immediately prior to the
Termination Date or (ii) the semi-monthly salary paid to Employee by Employer
which was in effect prior to any reduction thereof made without the written
consent of Employee, in either case multiplied by twenty-four (24).

         "Change of Control" shall mean any Transaction or series of
Transactions involving Employer or any Affiliate of Employer which results in
either (i) AMHC not directly or indirectly owning or controlling shares of stock
of the Employer sufficient to cast a majority of the votes necessary to elect
members of the Board of Directors of the Employer ("Voting Control"); (ii) the
individuals who, prior to such Transaction, constituted the board of directors
of AMHC ceasing to constitute at least a majority thereof, unless the election,
or the nomination for election of each director of AMHC for a period of two (2)
years following the consummation of such Transaction was approved by a vote of
at least two-thirds of the directors of AMHC then still in office who were
directors of AMHC prior to such Transaction; (iii) the individuals who, prior to
such Transaction, constituted the board of directors of Employer ceasing to
constitute at least a majority thereof, unless the election, or the nomination
for election of each director of the Employer for a period of two (2) years
following the consummation of such Transaction was approved by a vote of at
least two-thirds of the directors of Employer then still in office who were
directors of Employer prior to such Transaction; or (iv) the acquisition by any
Person other than AMHC or its subsidiaries of the beneficial ownership, as
defined in Rule 13d-3 of the Securities Exchange Act of 1934, of more than
twenty-five percent (25%) of the shares of stock of the Employer which are
entitled to elect the board of directors of the Employer at any time that AMHC
does not have beneficial ownership of the Voting Control of the Employer;
provided, however, that in the case of (i), (ii) and (iii), a Transaction which
is a Demutualization shall not constitute a Change of Control if the directors
elected or nominated for election to either AMHC's or Employer's respective
board of directors by AMHC's or Employer's respective stockholders following the
Demutualization were the directors of AMHC or Employer, respectively, prior to
such Demutualization, or if the election, or the nomination for election, by
AMHC's or Employer's respective stockholders, of each director of AMHC or
Employer, respectively, for a period of two (2) years following the consummation
of such Demutualization was approved by a vote

                                       1

<PAGE>   8

of at least two-thirds of the directors of AMHC or Employer then still in office
who were the respective directors of AMHC or the Employer prior to such
Demutualization.

         "Comparable Employment" shall mean employment with Employer, an
Affiliate thereof or a third party involved in any Change of Control on terms
and conditions (including without limitation geographic location) which in the
aggregate are at least substantially comparable to the terms and conditions of
employment prevailing with respect to Employee immediately preceding a Change of
Control.

         "Continued Benefits" shall mean the benefits described in Section 7
hereof.

         "Demutualization" shall mean any transaction in which more than fifty
percent (50%) of the assets of AMHC are (i) distributed or otherwise transferred
to the members of AMHC or (ii) are offered to the members of AMHC.

         "Good Reason" shall mean the occurrence of both (i) a Change of Control
without Employee being offered Comparable Employment and (ii) a Material Event.

         "Material Event" shall mean the occurrence of any one of the following
events following a Change of Control without Employee's express written consent:

         (1)      The assignment to Employee of duties substantially
                  inconsistent with Employee's position, duties, responsibility
                  or status with Employer or a substantial reduction of
                  Employee's duties or responsibilities, as compared with
                  Employee's duties or responsibilities prior to such reduction,
                  or any removal of Employee from, or any failure to re-elect
                  Employee to, the position Employee held at the time of such
                  removal or failure to re-elect, except in connection with
                  termination of employment for Cause; or

         (2)      A reduction in the amount of Employee's Base Compensation, a
                  material reduction in payments received by Employee under any
                  bonus or incentive plans in which Employee participates or a
                  material reduction in any other employee perquisites to which
                  Employee is entitled; or

         (3)      The relocation of Employee's principal office to a location
                  more than thirty-five (35) miles from the location of such
                  office immediately prior to such relocation; or

         (4)      Any material breach by Employer of any of the provisions of
                  this Agreement.

         "Notice of Termination" shall mean written notice of the termination of
the employment of Employee.

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

                                       2

<PAGE>   9


         "Plans" shall mean, collectively, the AllHAAmerUs Savings & Retirement
Plan, the AllHAAmerUs Supplemental Executive Retirement Plan, the AllyHAmerUs
Excess Benefit Plan, the Interim Benefit Supplement, any trust agreements
related to the foregoing and any successor plans.

         "Severance Payment" shall mean the payment described in Section 6
hereof.

         "Termination Date" shall mean the date on which the employment of
Employee with Employer terminates.

         "Transaction" shall mean any merger, consolidation, tender or exchange
offer, dissolution, liquidation, sale or exchange of stock, business
combination, sale or exchange of all or substantially all assets,
demutualization or other similar transaction or combination of the foregoing by
or between persons who were not under common control prior to such transaction.


                                       3