HUMANA SUPPLEMENTAL EXECUTIVE RETIREMENT AND SAVINGS PLAN

Exhibit 10(d)

HUMANA SUPPLEMENTAL EXECUTIVE

RETIREMENT

AND SAVINGS PLAN

AMENDED AND RESTATED AS OF

JUNE 25, 2009

TABLE OF CONTENTS

TABLE OF CONTENTS

TABLE OF CONTENTS

HUMANA SUPPLEMENTAL EXECUTIVE RETIREMENT

AND SAVINGS PLAN

AMENDED AND RESTATED AS OF

JUNE 25, 2009

WHEREAS, HUMANA INC. (“Humana”), a Delaware corporation with its principal place of business in Louisville, Kentucky (“Sponsoring Employer”), has adopted the Humana Retirement and Savings Plan (“Retirement and Savings Plan”), which is intended to be qualified under Section 401(a) of the Internal Revenue Code of 1986, as amended (“Code”), and

WHEREAS, certain employees of the Sponsoring Employer and its subsidiaries are eligible for allocations of contributions to retirement accounts and pretax savings accounts under the Retirement and Savings Plan and the Humana Puerto Rico 1165(e) Retirement Plan and plans previously terminated or merged into the Retirement and Savings Plan (collectively, “Qualified Plans”), and

WHEREAS , pursuant to the terms of the Qualified Plans, the benefits of certain employees of the Sponsoring Employer and its subsidiaries have been and will be reduced because of the limitation on compensation of Section 401(a)(17) of the Code, the nondiscrimination requirements of Sections 401(k) and 401(m) of the Code, the limitation on allocations of contributions of Section 415 of the Code and certain other limitations imposed by applicable provisions of the Puerto Rico Internal Revenue Code, and

WHEREAS , the Board of Directors of the Sponsoring Employer (“Board of Directors”) desires to continue to provide a supplemental benefit to a select group of management and highly compensated employees in the amount of the reduction of their benefits and employer contributions under the Qualified Plans, and

WHEREAS , on September 1, 1982, the Sponsoring Employer adopted the Humana Supplemental Executive Retirement Plan, and

WHEREAS , on May 11, 1988, the Sponsoring Employer adopted the Humana Thrift Excess Plan, and

WHEREAS , on December 31, 2003 the Sponsoring Employer merged the Humana Supplemental Executive Retirement Plan and the Humana Thrift Excess Plan, and amended and restated those plans as a single plan, namely the Humana Supplemental Executive Retirement and Savings Plan (the “Plan”), and

WHEREAS , the Sponsoring Employer now desires to amend the Plan to comply with Section 409A and to make certain other changes to the Plan.

NOW, THEREFORE, the Sponsoring Employer, pursuant to the right to amend the Plan contained in Article 7, hereby approves and adopts this amendment and restatement effective June 25, 2009, except for the modifications to Section 2.23 which shall be effective January 1, 2010.

ARTICLE 1

PURPOSE AND APPLICABILITY OF PLAN

1.1 Purpose of Plan. The purpose of the Plan shall be to provide Supplemental Benefits to Participants whose benefits under the Qualified Plans have been or will be reduced because of the compensation limitation of Section 401(a)(17) of the Code, the nondiscrimination requirements of Sections 401(k) and 401(m) of the Code and certain limitations imposed by applicable provisions of the Puerto Rico Internal Revenue Code, upon the terms and conditions, and subject to the limitations, contained herein.

1.2 Applicability of Plan. The provisions of the Plan shall apply only to persons participating in Qualified Plans on and after the applicable dates specified in Section 3.1.

ARTICLE 2

DEFINITIONS

As used herein, the following words and phrases shall have the meanings specified below, unless a different meaning is plainly required by the context. Terms not defined herein shall have the meanings specified in the Retirement and Savings Plan.

2.1 Accounts . A Participant’s Supplemental Retirement Account, Supplemental Pretax Savings Account and OTRP Rollover Account.

2.2 Beneficiary and Secondary Beneficiary. The person or persons (or a trust) as set forth under the Qualified Plans unless a Participant shall have elected in writing a different Beneficiary and Secondary Beneficiary for this Plan, in which case the written election for this Plan shall govern.

2.3 Board of Directors. The Board of Directors of the Sponsoring Employer.

2.4 Change in Control. Change in Control shall have the meaning set forth in Appendix A.

2.5 Code. The Internal Revenue Code of 1986, as it has been and may be amended from time to time. Reference to any section of the Code shall include any provision successor thereto.

2.6 Compensation Committee. The Organization and Compensation Committee of the Board of Directors of the Sponsoring Employer.

2.7 [Reserved.]

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2.8 Employee . Any member of a select group of management and highly compensated employees employed by an Employer.

2.9 Employer. The Sponsoring Employer and each corporation which is a member of the “affiliated group” (as defined in Section 1504(a) of the Code) with the Sponsoring Employer. When used with reference to an Employee or Participant, the term shall mean the Employer employing the Employee or Participant.

2.10 Initial Year Contribution. Contributions made to the Accounts of a Participant pursuant to Section 4.1 of the Plan, in respect of the year in which the Participant’s Participation Date occurred, including all gains (or losses) attributable to such contributions.

2.11 Investment Options. The investment vehicles in which a Participant’s Accounts shall be deemed invested. Investment Options shall be limited to those offered to participants in the Retirement and Savings Plan as of that date; provided, however, that no Participant shall be permitted to invest in a brokerage account.

2.12 OTRP Rollover Account. The account which reflects balances transferred from the Humana Officers’ Target Retirement Plan on November 1, 2007.

2.13 Participant. An Employee who has met the requirements of Article 3 for participation hereunder. Where the context so permits or requires, the term shall also include a person who was a Participant prior to the termination of the Participant’s employment with an Employer and who is entitled to a Supplemental Benefit after such person’s employment terminates.

2.14 Payment Commencement Date. The date on which the payment of a Participant’s Supplemental Benefits are scheduled to be paid or commence pursuant to Article V and the applicable election of the Participant.

2.15 Participation Date. The later of the applicable date specified in Section 3.1 or the date a Participant receives the notice described in Section 3.3.

2.16 Plan. The Humana Supplemental Executive Retirement and Savings Plan provided for herein, as it may be amended from time to time.

2.17 Plan Administrator. The Plan Administrator shall be the Sponsoring Employer.

2.18 Plan Year. The twelve consecutive month period commencing on the first day of January and ending on the last day of the immediately following December.

2.19 Qualified Plans. Each of the Humana Retirement and Savings Plan and the Humana Puerto Rico 1165(e) Retirement Plan.

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2.20 Qualified Pretax Savings Account. The Pretax Savings Account of a Participant in a Qualified Plan.

2.21 Qualified Retirement Account. The Retirement Account of a Participant in a Qualified Plan.

2.22 Related Employer. Any subsidiary or affiliate of the Sponsoring Employer, which is designated by the Board of Directors to be a Related Employer.

2.23 Retirement. A Participant’s retirement on or after the first day of the month coincident with or following the date on which all of the following shall have occurred:

(a) the Participant has completed five years of retirement service;

(b) the Participant has reached at least age 55; and

(c) the Participant’s age plus years of retirement service equals or exceeds 65.

A Participant’s “years of retirement service” shall be determined as provided for in the Retirement and Savings Plan.

2.24 Retirement and Savings Plan. The Humana Retirement and Savings Plan, as it may be amended from time to time.

2.25 Section 409A. Section 409A of the Code and the regulations and interpretive guidance issued thereunder.

2.26 Separation from Service. A Participant will be treated as having a Separation from Service if it is not reasonably expected that the Participant will continue to provide services to the Sponsoring Employer or any other Employer who has adopted the Qualified Plans (whether as an employee or independent contractor, but not as a director) that exceeds twenty percent (20%) of the average level of bona fide services performed by the Participant over the immediately preceding thirty-six (36) month period (or the full period of services if the Participant has been providing services less than thirty-six (36) months).

2.27 Sponsoring Employer. Humana Inc., a Delaware corporation.

2.28 Supplemental Benefits. The benefits available under the Plan, including the Supplemental Retirement Benefit, the Supplemental Pretax Savings Benefit, and the amount credited to the OTRP Rollover Account, unless otherwise specified.

2.29 Supplemental Pretax Savings Account. The account established by that name on behalf of a Participant.

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2.30 Supplemental Retirement Account. The account established by that name on behalf of a Participant.

2.31 Supplemental Pretax Savings Benefit. The benefit described in Section 4.1(b).

2.32 Supplemental Retirement Benefit. The benefit described in Section 4.1(a).

ARTICLE 3

PARTICIPATION IN THE PLAN

3.1 Eligible Employees. Persons eligible to participate in the Plan include (i) each Employee who is a participant in a Qualified Plan (a) after August 31, 1982, in the case of the Supplemental Retirement Account and (b) May 1, 1988, in the case of the Supplemental Pretax Savings Account and (ii) as of November 1, 2007, in the case of persons whose accounts have been transferred to the Plan from the Humana Officers’ Target Retirement Plan. Participants shall participate in this Plan to the extent of the benefits stated herein.

3.2 Provisions of Plan Binding on Participants. Upon becoming a Participant, a Participant shall be bound then and thereafter by the terms of this Plan, including all amendments to the Plan.

3.3 Notification of Participation. Each Employee shall become a Participant on the date he or she receives notification to that effect.

3.4 Termination of Benefit Accrual. An Employee’s accrual of benefits under this Plan shall cease upon the Employee’s Separation from Service.

ARTICLE 4

SUPPLEMENTAL BENEFITS

4.1 Amount of Supplemental Benefits.

(a) Supplemental Retirement Benefits. Each Participant shall become entitled to Supplemental Retirement Benefits for a Plan Year equal to the difference, if any, between the actual contribution by the Employer to a Qualified Retirement Account on behalf of the Participant for such Plan Year and the amount of the contribution which would otherwise have been made by the Employer on behalf of such Participant for such Plan Year but for the compensation limitation of Section 401(a)(17) of the Code and the annual additions limitations imposed by Section 415 of the Code, and effective January 1, 2008 with respect to limitations imposed by applicable sections of the Puerto Rico Internal Revenue Code.

(b) OTRP Rollover Benefits. Amounts that have been transferred to the Plan in respect of a Participant’s accrued benefit under the Humana Officers’ Target Retirement Plan shall be allocated to the Participant’s OTRP Rollover Account as of November 1, 2007.

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(c) Supplemental Pretax Savings Benefits. Each Participant shall become entitled to Supplemental Pretax Savings Benefits for a Plan Year equal to the difference, if any, between the actual Employer matching contribution to a Qualified Pretax Savings Account made on behalf of the Participant for such Plan Year and the amount the Employer matching contribution would otherwise have been on behalf of such Participant for such Plan Year but for the legal limitations on the Participant’s contributions and the Employer’s contributions, and effective January 1, 2008 with respect to limitations imposed by applicable section of the Puerto Rico Internal Revenue Code; provided, however, that for Plan Years beginning before 2008, Participants shall be entitled to benefits under this section only if such difference is equal to or greater than eight hundred dollars ($800.00) in such Plan Year.

4.2 Accrual of Supplemental Benefits. The Supplemental Retirement Benefit and the Supplemental Pretax Savings Benefit shall be deemed to accrue to the Participant’s Supplemental Retirement Account and Supplemental Pretax Savings Account no later than the date on which the annual retirement contribution is made to the applicable Qualified Plan. No benefit will accrue with respect to any Plan Year if the Participant ceases to be an active employee before the end of such Plan Year, unless cessation of employment is due to death, Retirement, disability or a Change in Control, in which case the Participant will be entitled to benefits prorated to the date on which the Participant ceases to be an active employee.

4.3 Investment Options.

(a) Accruals for Plan Years Prior to and Including 2006 . With respect to accruals made to a Participant’s Supplemental Retirement Account and Supplemental Pretax Savings Account for plan years prior to and including 2006, accruals were allocated among the Investment Options in accordance with the allocation of a Participant’s Retirement and Savings Plan account. Such allocations were effected at such times and with such exceptions as were established by the Administrator.

(b) Accruals for Plan Years After 2006 . Each Participant shall elect the Investment Options in which accruals to the Participant’s Supplemental Retirement Account and Supplemental Pretax Savings Account shall be deemed to be allocated. A Participant’s accruals may be allocated in one percent increments among one or more of the Investment Options. If the Participant allocates less than 100% of his or her accruals pursuant to this Section 4.3(b), unallocated accruals shall be deemed to be allocated to the default investment option established by the Plan Administrator, or if no such default has been established by the Plan Administrator, to the default investment option established under the Retirement and Savings Plan. A Participant may change the allocation of accruals to his or her Supplemental Retirement Account and Supplemental Pretax Savings Account at any time in such manner as the Plan Administrator may prescribe.

(c) OTRP Rollover . Amounts allocated to a Participant’s OTRP Account shall initially be deemed to be invested in the applicable age appropriate target retirement fund Investment Option. Subsequently, a Participant may reallocate the balance in his or her OTRP Rollover Account pursuant to Section 4.4.

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4.4 Reallocation Among Investment Options. Each Participant may reallocate the balances in his or her Accounts among the Investment Options in one percent increments. Effective November 1, 2007, changing Investment Options shall be permitted on a daily basis and shall be effected in such manner as the Plan Administrator may prescribe from time to time, which may include an online alternative.

4.5 Adjustments to Account Balances. The balances in Participants’ Accounts shall be adjusted for gains (or losses) as if such amounts were actually invested in the Investment Options selected by the Participants. Upon a Participant’s Separation from Service or cessation of active participation in this Plan for any reason, the balances in the Participant’s Accounts will continue to be allocated among the Investment Options subject to reallocation pursuant to Section 4.4.

ARTICLE 5

DISTRIBUTION OF BENEFITS

5.1 Eligibility for Distribution of Supplemental Benefits. Except as otherwise provided in Article 5, the payment of the Participant’s Supplemental Benefits shall commence no later than ninety (90) days following the Participant’s Separation from Service (the “ Payment Commencement Date ”). The form of the payment shall be governed by Section 5.2 notwithstanding the form of distribution of the Participant’s benefits from the Retirement and Savings Plan. All payments shall be made in cash.

5.2 Form of Payment. If a Participant does not elect an alternative form of distribution in accordance with Section 5.3, the Participant’s distribution will be made in the form of a lump sum distribution.

5.3 Initial Election of Form of Distribution . Prior to the later of December 31, 2008 and the date that is thirty (30) days after a Participant’s Participation Date, a Participant may elect one of the following alternative forms of distribution for amounts other than the Initial Year Contribution:

(a) Periodic installments (either monthly, quarterly or annually) for a period not to exceed 20 years, to the extent permitted under Section 409A; provided, however, that this form of payment will only be available if the Participant’s balance in the account from which the periodic payments would be made exceeds $100,000, or such lesser amount, if any, permitted under Section 409A. In the event that the benefit payments are in the form of installments, the Participant’s Accounts shall be deemed to be invested in the Stable Value Fund or a fund similar to the Stable Value Fund then available under the Retirement and Savings Plan; or

(b) An annuity in any form permitted from the Retirement and Savings Plan at the time of a Participant’s election; provided, however, that an annuity form of payment will only be available if the Participant’s balance in the account from which the annuit