The following description of the LabOne, Inc. Profit Sharing 401(k) Plan (the Plan) provides only general information. Participants should refer to the Summary Plan Description for a more complete description of the Plan's provisions.

The Plan is a defined contribution plan adopted by the board of directors of LabOne, Inc. (the Company) established to cover all full-time employees of the Company. The Plan was effective January 1, 1987. Employees of the Company are eligible for participation at the beginning of each calendar quarter following the date the employee completes five hundred hours of service, attains age 20 1/2, and completes six consecutive months of employment or one year of eligibility service, as defined. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974 (ERISA).

The Plan allows participating employees to exclude their contributions from current taxable income. Contributions made by the Company and participating employees will not be required to be included in the employees' taxable income until the year of withdrawal from the Plan.

Participant contributions - The Plan establishes a qualified cash or deferred arrangement permitting eligible employees to authorize the Company to make tax-deferred salary reduction contributions on their behalf up to 15% (10% prior to January 1, 2002) of their annual earnings, as defined by the Plan, and subject to certain limitations under the Internal Revenue Code (the Code) (not to exceed $13,000 in 2004 and $12,000 in 2003). Additionally, new legislation allows participants who will attain the age of 50 during 2004 and 2003 to contribute an additional $3,000 and $2,000 catch-up contribution, respectively. Participants may also contribute amounts representing distributions from other qualified defined benefit or defined contribution plans. Participants may elect to change their investment allocations daily and may elect to transfer funds between accounts throughout the year.

Severance pay for highly compensated employees is not considered compensation for Plan purposes. Therefore, highly compensated employees are restricted from making Plan contributions from severance pay.

Employer contributions - The Company has the discretion to contribute up to an additional 50% of each participant's contributions, not to exceed 10% of the participant's annual compensation. The Company elected to contribute the maximum amount for 2004, 2003, and 2002. Since 1987, all Company contributions have been invested in Company common stock.

Each participant's account is credited with the participant's contribution and allocations of (a) the Company's contribution and (b) Plan earnings and charged with an allocation of administrative expenses. Allocations are based on participant earnings or account balances, as defined. The benefit to which a participant is entitled is the benefit that can be provided from the participant's vested account.

Participants may transfer funds between accounts at any time upon notification to the Plan record keeper, JPMorgan Chase. Prior to 2002, participants could not allocate Company contributions to other investment options, as they were required to be invested in Company common stock. In 2002, the Plan was amended to allow participants with at least three years of vested service to allocate up to 50% of the Company stock held in their account to other investment options offered by the Plan. Beginning January 1, 2003, all participants may allocate all vested shares of Company stock to other investment options offered by the Plan.

Distributions of vested balances are available upon termination, subject to the approval of the plan administrator, retirement at or after age sixty-five, death, or permanent and total disability. Distributions can be made in either a lump sum or annuity to designated beneficiaries and joint survivors. A participant may at any time withdraw any portion of his or her employee account upon showing financial hardship, as permitted by the Code.

Participants are vested immediately in their contributions plus actual earnings thereon. Vesting in the Company's contribution portion of their accounts is based on years of continuous service. Through December 31, 2001, participants became 100% vested in Company contributions after completing five years of service. In 2002, the vesting schedule was amended to allow participants 100% vesting after completion of three years. Each participant is 100% vested in the employer contributions upon disability, death, or attainment of age sixty-five while employed by the Company.

Loans to participants may be authorized by the Plan's Administrative Committee. The amount may not be less than $500 and may not exceed one-half of the participants' vested account balances (limited to $50,000). Loans must carry a reasonable rate of interest defined as not less than the prime rate plus 1% on the date of the last day of the month preceding loan issuance. The loan repayment period may vary from one to five years.

Forfeitures represent the nonvested portion of participant account balances upon termination. Forfeited amounts are applied to reduce future Company contributions. During 2004, 2003, and 2002, Company contributions were reduced by $131,251, $103,000, and $119,073, respectively, due to forfeited nonvested accounts. The balance of unallocated forfeitures to be used to offset future Company contributions was $19,764 and $112,882 at December 31, 2004 and 2003, respectively.

On December 1, 2002, the Company acquired all the outstanding stock of Central Plains Laboratories, LLC. Effective July 1, 2003, the Central Plains Laboratories, LLC Profit Sharing 401(k) Plan was merged with the Plan and the remaining assets of $1,504,146 were transferred to the Plan. Following the merger, participants directed the allocation of the remaining assets among the various investment options offered by the Plan.

The accompanying financial statements have been prepared on the accrual basis in conformity with accounting principles generally accepted in the United States of America.

The Plan's investments are held in a bank trust account. Investments in securities are stated at fair value, except for the common commingled trust (see note 10). The fair value of marketable securities is based upon quotations from national securities exchanges. Plan assets include investments in common stock of the Company. Net appreciation (depreciation) in fair value of investments includes both realized and unrealized gains and losses on securities held by the funds. Purchases and sales of investments are recorded on a trade-date basis. Dividends are recorded on the ex-dividend date.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires the plan administrator to make estimates and assumptions that affect the reported amounts of net assets available for benefits at the date of the financial statements and the reported amounts of changes in net assets available for benefits during the reporting period. Actual results could differ from those estimates.

Benefits are recorded when paid.

The following table presents investments that represent 5% or more of the Plan's net assets at December 31, 2004 and 2003:

During the years ended December 31, 2004, 2003, and 2002, the Plan's investments (including gains and losses on investments bought and sold, as well as held during the year) appreciated (depreciated) in value as follows:

At June 8, 2005, the fair value of the 754,251 shares of common stock of the Company held by the Plan at December 31, 2004 was $30,170,040.

Company contributions are invested in Company common stock. Employees can also elect to invest their contributions in Company common stock. Information about the net assets and the significant components of the changes in net assets relating to both the nonparticipant- and participant-directed investment in Company common stock for the years ended December 31, 2004, 2003, and 2002 is as follows:

The Plan has received a determination letter from the Internal Revenue Service, dated November 7, 2002, stating that the Plan meets the requirements of Section 401(a) of the Code and the trust is exempt from Federal income taxes under the provisions of Section 501(a) of the Code. The plan administrator is not aware of any activity or transactions that may adversely affect the qualified status of the Plan.

Although the Plan has been amended since receiving the determination letter, the plan administrator believes that the Plan is designed and is currently being operated in compliance with the applicable requirements of the Code.

Certain administrative functions are performed by officers or employees of the Company. No such officer or employee receives compensation from the Plan. Substantially all administrative expenses for the Plan are paid by the Company.

Investments include cash at JPMorgan Chase. JPMorgan Chase is the record-keeper and trustee as defined by the Plan and, therefore, these transactions qualify as party-in-interest transactions. In addition, the Plan also holds shares of Company common stock.

At December 31, 2004 and 2003, participants whose account balances totaled $17,038 and $394,717, respectively, notified the plan administrator that they had elected to withdraw from the Plan. These amounts are presented herein as a component of net assets in the accompanying financial statements, but are presented as liabilities of the Plan on Form 5500.

The following is a reconciliation of net assets available for plan benefits from the financial statements to the Form 5500 at December 31, 2004 and 2003:

The following is a reconciliation of distributions to participants per the financial statements to the Form 5500 for the years ended December 31, 2004, 2003, and 2002:

The Plan is subject to the provisions of the ERISA. Although it has not expressed any intention to do so, the Company has the right to discontinue its contributions to the Plan at any time and to terminate the Plan subject to the provisions set forth in ERISA. In the event of termination, participants would become 100% vested in their employer contributions.

In 2004, the Plan entered into a benefit-responsive commingled trust. The trust is the American Century Stable Asset Fund and maintains the contributions in a general account. The account is adjusted periodically to reflect the performance of the underlying investment securities less any expenses of the Plan. The trust is included in the financial statements at contract value as reported to the Plan by the trust. Contract value represents contributions made under the contract, plus earnings, less participant withdrawals and administrative expenses. Participants may ordinarily direct the withdrawal or transfer of all or a portion of their investments at contract value.