HMS Holdings Corp., a New York-based benefits coordinator for payers, has signed a definitive agreement to acquire privately held HealthDataInsights, Las Vegas, a recovery audit contractor technology firm, for approximately $400 million.

The deal calls for HDI to become a wholly owned subsidiary of HMS Holdings Corp. and for HDI founder, President and CEO Andrea Benko to continue in her current roles. HDI employs about a total of 400 people at the company's headquarters in Las Vegas and in facilities in California and Florida.

The deal will consist of $384 million in cash paid at closing and approximately $16 million in the assumption of unvested stock options, according to a news release. The assumed options will be adjusted as to exercise price and number of shares to convert them into options for HMS stock. HMS also plans to establish a $100 million bank revolving credit facility in connection with the deal. Using HMS' revenue recognition methodology, HDI is projected to add about $85 million of revenue to HMS in 2012, according to the release.

The deal, which is expected to close by the end of the year, is subject to regulatory approval.

Earlier this year, HMS named Cynthia Nustad chief information officer.