Caremark Rx, Inc. Announces the Tender of 97.87% of AdvancePCS 8 1/2% Senior Notes Due 2008; Extends the Tender Offer and Consent Solicitation.

Business Editors

NASHVILLE, Tenn.--(BUSINESS WIRE)--March 15, 2004

Caremark Rx, Inc. (NYSE: CMX) announced today that, in connection with Cougar Merger Corporation's previously announced offer to purchase for cash any and all of the outstanding 8 1/2% Senior Notes due 2008 of AdvancePCS (CUSIP No. 00790K AB 5, ISIN US00790KAB52, Common Code 012977158) and related solicitation of consents to amend the Indenture governing the Notes, Caremark has been advised by The Bank of New York Trust Company, N.A., the depositary for the tender offer and consent solicitation, that, as of 5:00 p.m. New York City time, on March 12, 2004, holders of approximately 97.87% in aggregate principal amount of Notes outstanding have validly tendered and have not withdrawn their Notes and have delivered related consents.

Caremark also announced that Cougar Merger Corporation has extended the expiration date of the tender offer and consent solicitation for the Notes. Cougar Merger Corporation's obligation to accept the Notes for payment is subject to the terms and conditions set forth in the Offer to Purchase and Consent Solicitation Statement, dated February 18, 2004, including the completion of the proposed merger with AdvancePCS. As previously announced, on March 22, 2004, AdvancePCS's stockholders will vote, among other things, to approve the merger between Caremark and AdvancePCS, and Caremark stockholders will vote, among other things, to approve the issuance of shares of Caremark common stock to AdvancePCS stockholders in the merger.

The tender offer, previously scheduled to expire at 9:00 a.m. New York City time, on March 17, 2004, will now expire at 9:00 a.m. New York City time on March 23, 2004, unless further extended.

As provided in the Offer to Purchase and Consent Solicitation Statement, the consideration to be paid for the Notes tendered in the tender offer will be calculated at 2:00 p.m. New York City time, on the second business day immediately preceding the expiration date, as extended. Therefore, the consideration to be paid for the Notes tendered in the tender offer is expected to be calculated at 2:00 p.m., New York City time on March 19, 2004, unless the expiration date is further extended.

This announcement does not constitute an offer to purchase, a solicitation of an offer to purchase or a solicitation of an offer to sell securities with respect to any Notes. The tender offer and consent solicitation are being made solely on the terms and conditions set forth in the Offer to Purchase and Consent Solicitation Statement and the accompanying transmittal documents. For additional information regarding the tender offer and consent solicitation, reference should be made to the Offer to Purchase and Consent Solicitation Statement and the related transmittal documents. UBS Investment Bank is acting as dealer manager for the tender offer and consent solicitation. Georgeson Shareholder Communications Inc. is acting as information agent.

Holders of the Notes with questions regarding the tender offer and consent solicitation may contact the Liability Management Group at UBS Investment Bank, [phone] (collect) or [phone] x 4210 (toll-free). Requests for copies of the offer to purchase and consent solicitation statement and the related transmittal documents should be directed to Georgeson Shareholder Communications Inc., [phone] (collect) or [phone] (toll-free).

About Caremark Rx, Inc.

Caremark Rx, Inc. is a leading pharmaceutical services company, providing comprehensive drug benefit services through its affiliate Caremark Inc. to over 1,200 health plan sponsors and their participants throughout the U.S. Caremark's clients include corporate health plans, managed care organizations, insurance companies, unions, government agencies and other funded benefit plans. The company operates a national retail pharmacy network with over 55,000 participating pharmacies, four state-of-the-art mail service pharmacies, the industry's only FDA-regulated repackaging plant and nineteen specialty distribution mail service pharmacies for delivery of advanced medications to individuals with chronic or genetic diseases and disorders.

Safe Harbor Statement

This press release contains statements that constitute "forward-looking statements" within the meaning of the Securities Act of 1933 and the Securities Exchange Act of 1934, both as amended by the Private Securities Litigation Reform Act of 1995. These statements are based on the current expectations of management. There are a number of risks and uncertainties that could cause actual results to differ materially from the expectations of management. You are encouraged to consult the filings which Caremark Rx, Inc. makes with the Securities and Exchange Commission under both the Securities Act of 1933 and the Securities Exchange Act of 1934 for more information concerning such risks and uncertainties. You are cautioned not to place undue reliance on these forward-looking statements which speak only as of the date stated, or if no date is stated, as of the date of this press release.

Additional information about Caremark is available on the World Wide Web at www.caremarkrx.com.