a. Contributions: The Plan maintains two accounts, the Pretax Savings Account and the Retirement Account, a profit sharing account.

Any employee of the Company who is employed with a sponsoring employer is eligible to participate in the Plan's Pretax Savings Account beginning on the employee's date of hire. A participant, through payroll deductions, may contribute not less than 1% nor more than 10% of the participant's annual compensation, not to exceed the Puerto Rico Tax Code limitation in effect for the calendar years, which was $8,000 for 2005 and 2004.

The Company enrolls eligible participants at 3% of compensation 45 days after the employee's date of hire, unless the employee elects not to participate in the Pretax Savings Account or elects a different percentage up to 10%. The Company's matching contribution is equal to 50% of the participant's contribution up to 6% of the participant's annual compensation for any participating employee. The Board of Directors of the Company, at its option, may increase this matching percentage up to 100%. All matching contributions are funded bi-weekly and are invested in the Humana Stock Fund. Once the matching contributions are funded, participants can transfer the matching contributions among any funds within the Plan. The Humana Stock Fund, a participant directed commingled fund that invests primarily in the Company's common stock with a minor portion of short-term investments. Ownership in the Humana Stock Fund is measured by units rather than shares of common stock.

After an employee completes two years of service with a sponsoring employer and has complied with certain other service requirements, the employee becomes eligible to participate in the profit sharing feature of the Plan. For the plan years ended December 31, 2005 and 2004, the Company declared a profit sharing contribution of approximately $532,000 and $493,000, respectively. This contribution was made into the Retirement Account of the Plan and was allocated to the participants based on an amount equal to 4% of each participating employee's qualifying compensation earned during the plan year, plus 4% of any compensation that exceeds the social security taxable wage base. Contribution amounts are computed as of the end of each plan year and are nonforfeitable.

Contributions to the Plan by or on behalf of employees may be restricted in amount and as to timing so as to meet various requirements of the Internal Revenue Code (IRC) of 1986, as amended.

Each participant's account is credited with the participant's contributions, the Company's contributions, the allocations of Plan earnings, and charged with an allocation of administrative expenses. Allocations are based on participants' account balances.

Participants may allocate contributions to the Pretax Savings Account and the Company's contribution to the Retirement Account among various investment options in 1% increments. The Plan offers nine mutual funds, the Humana Stock Fund, and the Schwab Personal Choice Retirement Account (PCRA), which is a self-directed brokerage account, as investment options. In the absence of such allocation, contributions are invested in the Primco Stable Value Fund. In connection with a change in allocation of a participant's or the Company's future contributions among the eleven investment options and a change in the investment of existing accounts, the purchases and sales due to fund transfers are transacted at the funds' net asset value on the day the transaction is initiated.

Employee contributions are nonforfeitable. Participants who withdraw from the Pretax Savings Account prior to being credited with three years of service with the Company will forfeit the employer contributions. Once a participant has completed three years of service, the employer contributions become totally nonforfeitable.

b. Forfeitures: Forfeited balances of terminated participants' nonvested accounts are used to reduce future Company contributions. The benefit to which a participant is entitled is the benefit that can be provided from the participant's vested account. Employer contributions, forfeited as a result of withdrawal following termination of employment, will be available to reduce the amount of subsequent employer contributions to the Pretax Savings Account. If a former participant is re-employed prior to five consecutive one-year breaks in service and repays the amount of his/her distribution, then any forfeited employer contributions are restored to his/her account.

At December 31, 2005 and 2004, forfeited non-vested accounts totaled $298 and $75, respectively. These accounts will be used to reduce future employer contributions. Also, in 2005 and 2004, employer contributions were reduced by $9,950 and $7,297 from forfeited nonvested accounts.

c. Withdrawals: The value of a participant's interest, including employer contributions, is generally payable upon the occurrence of one of the following events: (1) the participant's termination of employment; (2) a determination by the Company upon competent medical or other evidence that, by reason of permanent and total disability, the participant is incapable of performing the duties of his/her work; or (3) the participant's death.

In the event funds are needed because of extreme financial hardship, as defined by law, the participant may be allowed to make a withdrawal of his/her vested account balance. In addition, the Plan contains restrictions relating to minimum withdrawals and the frequency of withdrawals.

Benefits under the Plan are payable to withdrawing participants, including retirees, as follows:

If the vested account balance is less than $1,000, a lump-sum distribution will be made.

The Plan permits the employee to roll over contributions to another qualified plan. An employee must make a written request to the Plan for a rollover contribution. These contributions must comply with certain requirements before the Plan will authorize the rollover contribution.

Participants may borrow from their fund accounts. The aggregate of the loans to a participant shall not exceed the lesser of $50,000 or 50% of the vested portion of his/her participant contribution accounts, voluntary contribution accounts, plus his/her employer Pretax Savings Account to which he/she would be entitled to if he/she incurred a termination of employment. The minimum amount a participant may borrow is $1,000. Loan transactions are treated as a transfer to (from) the various investment funds from (to) the Participant Notes Receivable. Loan terms range from one to four years or up to ten years for the purchase of a primary residence. The loans are collateralized by the balance in the participant's account and bear interest at a reasonable rate in accordance with the Department of Labor's Rules and Regulations for Reporting and Disclosure under ERISA, as determined by the Plan Administrator. Principal and interest are repaid ratably through payroll deductions.

a. Basis of Accounting: The financial statements of the Plan are prepared under the accrual method of accounting. Withdrawals by participants are recorded when paid. Purchases and sales of securities are recorded on a settlement-date basis which approximates trade date. Interest income is recorded on the accrual basis. Dividends are recorded on the ex-dividend date.

b. Valuation of Investments: The Plan's investments in common/collective trusts and mutual funds are valued at quoted market prices that represent the net asset value of shares held by the Plan at year end. The Humana Stock Fund is comprised of shares of the Company's common stock and a small portion of short-term investments. The Humana Stock Fund is measured by units and is valued based on the quoted closing market price of the Company's common stock. Participant loans and investments in money market funds are valued at cost, which approximates fair value. The PCRA is a self-directed brokerage account, which is comprised of various investments such as cash, common stock, mutual funds, U.S. Governmental securities, and corporate bonds, and is valued based on quoted market prices.

Investments in traditional and synthetic guaranteed investment contracts (GICs) with banks and insurance companies are fully benefit-responsive and are carried at contract value, which represents contributions, plus interest earned at specified rates, less withdrawals and administrative expenses.

The Plan presents in the accompanying statements of changes in net assets available for benefits the net appreciation or depreciation in fair value of investments, which consists of both realized gains or losses and unrealized appreciation or depreciation.

c. Management Estimates: The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of net assets available for benefits and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of additions to and deductions from net assets during the reporting periods. Actual results could differ from those estimates.

d. Recently Issued Accounting Pronouncements: On December 29, 2005, The Financial Accounting Standards Board (FASB) released FASB Staff Position No. AAG INV-1 and SOP 94-4-1, "Reporting of Fully Benefit-Responsive Investment Contracts Held by Certain Investment Companies Subject to the AICPA Investment Company Guide and Defined-Contribution Health and Welfare and Pension Plans (FSP)." The FSP clarifies the definition of fully benefit-responsive investment contracts for contracts held by defined contribution plans. The FSP also establishes enhanced financial statement presentation and disclosure requirements for defined contribution plans subject to the FSP effective for financial statements for issued for periods ending after December 15, 2006.

The Company intends to adopt the FSP in the Plan's financial statements for the year ended December 31, 2006. The effect of the FSP on the Plan's financial statements is expected to be enhanced financial statement presentation and disclosure requirements.

Benefit-responsive investment contracts (investments in bank collective investment funds that hold benefit-responsive investment contracts) will be presented at fair value on the statement of net assets available for benefits and the amount representing the difference between fair value and contract value of the investment contracts (or bank collective investment fund) shall be presented on the face of the statement of net assets available for benefits as a single amount, calculated as the sum of the amounts necessary to adjust the portion of net assets attributable to each fully benefit-responsive investment contract from fair value to contract value. The statement of changes in net assets available for benefits shall be prepared on a basis that reflects income credited to participants in the Plan and net appreciation or depreciation in the fair value of only those investment contracts that are not deemed to be fully benefit responsive.

e. Reclassifications: Certain prior year amounts have been reclassified to conform to the 2005 financial statement presentation.