Caremark Rx, Inc. Announces Increase in Stock Repurchase Program to $1.25 Billion.

NASHVILLE, Tenn. -- Caremark Rx, Inc. (NYSE: CMX) today announced that its Board of Directors has authorized a $500 million increase in its existing stock repurchase program, bringing the total authorized amount available for repurchase up to $1.25 billion of the Company's common stock in the open market. The repurchases will occur in the open market at times and in amounts as management deems appropriate. The number of shares repurchased will depend on a variety of factors, including price, regulatory requirements and market conditions.

"Due to the Company's performance and its significant cash flow generation, the Board has determined that an increase in the share repurchase program is an appropriate use of excess cash," said Mac Crawford, Chairman, President and Chief Executive Officer of Caremark. "The Board regularly assesses the repurchase program along with other strategies for deployment of capital to support Caremark's growth and to generate shareholder value."

On July 20, 2004, Caremark announced that the Board of Directors had authorized the Company to repurchase up to $750 million of the Company's common stock in the open market. As of May 16, 2005, the Company had repurchased a total of 22.8 million shares, at an approximate cost of $691 million, under the stock repurchase program.

About Caremark Rx, Inc.

Caremark Rx, Inc. is a leading pharmaceutical services company, providing through its affiliates comprehensive drug benefit services to over 2,000 health plan sponsors and their plan 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 59,000 participating pharmacies, seven mail service pharmacies, the industry's only FDA-regulated repackaging plant and 21 licensed specialty pharmacies for delivery of advanced medications to individuals with chronic or genetic diseases and disorders.

Forward-Looking 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 as amended by the Private Securities Litigation Reform Act of 1995. "Forward-looking statements" contained in this press release include the intent, belief or current expectations of the company and members of its senior management team with respect to activity relating to the stock repurchase program, as well as the assumptions upon which such statements are based. Prospective investors are cautioned that any such forward-looking statements are not guarantees of future performance, involve risks and uncertainties and that actual results may differ materially from those contemplated by such forward-looking statements. Important factors currently known to management that could cause actual results to differ materially from those contemplated by the forward-looking statements in this press release include, but are not limited to, adverse developments with respect to the company's operating plan and objectives, as well as adverse developments in the healthcare or pharmaceutical industry generally. Additional factors that could cause actual results to differ materially from those contemplated in this press release can be found in the company's Annual Report on Form 10-K for the year ended December 31, 2004 and the company's 10-Q for the three months ended March 31, 2005.

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