athenahealth Issues Clarification

CMS Claims Reprocessing Immaterial to Fiscal Year 2011 Results

WATERTOWN, Mass. (July 27, 2011) – athenahealth, Inc. (NASDAQ: ATHN), a leading provider of cloud-based business services for physician practices, wishes to clarify certain information regarding the amount of client collections associated with claims being reprocessed by the Centers for Medicare and Medicaid Services (CMS).

Following the athenahealth’s Q2 2011 earnings release on July 21, 2011, management has received a number of questions regarding the impact of claims being reprocessed due to corrections to the 2010 Medicare Physician Fee Schedule (MPFS) and certain provisions of the Affordable Care Act of 2010. Due to the retroactive dates of these corrections and the resulting claim volume, CMS began reprocessing claims with dates of service between January 1, 2010 and May 31, 2010 in February of 2011.

athenahealth wishes to clarify that the amount of client collections associated with this process during the first half of fiscal year 2011 was less than $5.0 million and that we expect the amount of client collections associated with this process during the second half of fiscal year 2011 to be similar in size. Overall, the CMS claims reprocessing is immaterial to athenahealth’s fiscal year 2011 results.

About athenahealth

athenahealth, Inc. is a leading provider of cloud-based business services for physician practices. athenahealth’s service offerings are based on proprietary web-native practice management and electronic health record (EHR) software, a continuously updated payer knowledge-base, integrated back-office service operations, and automated and live patient communication services. For more information, please visit www.athenahealth.com or call (888) 652-8200.

Forward-Looking Statements

This press release contains forward-looking statements, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, including statements reflecting management’s expectations for future financial and operational performance, and in particular our expectations regarding the amount of client collections associated with the reprocessing of claims by CMS. The forward-looking statements in this release do not constitute guarantees of future performance. These statements are neither promises nor guarantees, and are subject to uncertainties, which may be beyond the Company’s control and could cause actual results to differ materially from those contemplated in these forward-looking statements. In particular, the uncertainties include, among other things, the actual amount of client collections that could be impacted by the reprocessing of claims and the timing of such process. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. The Company undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances, or otherwise. For additional disclosure regarding these and other risks faced by the Company, see the disclosures contained in its public filings with the Securities and Exchange Commission, available on the Investors section of the Company’s website at http://www.athenahealth.com and on the SEC’s website at http://www.sec.gov.

Source: athenahealth