NxStage(R) Ranked 14th Fastest Growing Company in North America on Deloitte’s 2008 Technology Fast 500

Friday November 21, 2008

LAWRENCE, Mass., Nov. 21 /PRNewswire-FirstCall/ — NxStage Medical, Inc. (Nasdaq: NXTM), a leading manufacturer of innovative dialysis products, today announced that it ranked 14th on Deloitte’s 2008 Technology Fast 500, a ranking of the 500 fastest growing technology, media, telecommunications and life sciences companies in North America. Rankings are based on percentage of fiscal year revenue growth over five years, from 2003-2007. NxStage Medical, Inc. grew more than 20,000 percent during this period.

NxStage Medical’s CEO, Jeffrey H. Burbank, credits the significant health and quality of life benefits experienced by patients using NxStage’s innovative System One for home hemodialysis therapy, the cost and operational advantages of the System One within the critical care market, as well as the strength of the Company’s value-added in-center offerings for its significant revenue growth over the past five years.

Each company on Deloitte’s Technology Fast 500 is an innovator with an exceptional five-year track record of growth, said Phil Asmundson, Deloitte LLP vice chairman and national managing partner for Technology, Media and Telecommunications. NxStage has earned its position among the fastest growing companies in North America, and we are proud to honor this important accomplishment.

Fast 500 Selection and Qualifying Criteria

The Fast 500 ranks the fastest growing technology, media, telecommunications and life sciences companies in North America. It is compiled from Deloitte’s regional North American Fast 50 programs, nominations submitted directly to the Fast 500, and public company database research. Companies are selected based on percentage revenue growth from 2003 to 2007.

Entrants must own proprietary intellectual property or proprietary technology that contributes to a significant portion of the company’s operating revenues or devote a significant proportion of revenues to research and development of technology. Using other companies’ technology or intellectual property in a unique way does not qualify. Base-year operating revenues must be at least $50,000 USD or $75,000 CD, and current-year operating revenues must be at least $5 million USD or CD. Companies must be in business a minimum of five years, and they must be headquartered within North America.

About NxStage Medical

NxStage Medical, Inc. (Nasdaq: NXTM) is a medical device company, headquartered in Lawrence, Massachusetts, USA, that develops, manufactures and markets innovative dialysis systems for the treatment of end-stage renal disease, or ESRD, and acute kidney failure. For more information on NxStage and its products, please visit the company’s website at http://www.nxstage.com.

About Deloitte

As used in this document, Deloitte means Deloitte LLP. Please see http://www.deloitte.com/about for a detailed description of the legal structure of Deloitte LLP and its subsidiaries.

Forward-Looking Statements

This release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this release that are not clearly historical in nature are forward-looking, and the words anticipate, believe, expect, estimate, plan, and similar expressions are generally intended to identify forward-looking statements. All forward-looking statements involve risks, uncertainties and contingencies, many of which are beyond NxStage’s control, which may cause actual results, performance, or achievements to differ materially from anticipated results, performance or achievements, including market acceptance and demand for the NxStage System One, growth in home hemodialysis, and certain other factors that may affect future operating results and which are detailed in NxStage’s filings with the Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the quarter ended September 30, 2008. NxStage is under no obligation to (and expressly disclaims any such obligation to) update or alter its forward-looking statements, whether as a result of new information, future events or otherwise.

Kristen K. Sheppard, Esq.
VP, Investor Relations
NxStage Medical, Inc.
ksheppard@nxstage.com

SOURCE NxStage Medical, Inc.

Web site: http://www.nxstage.com
http://www.deloitte.com