Minneapolis-based Ability Network, a Web-based health care technology provider that links client hospitals and clinics with Medicare, will be acquired by Summit Partners, the Boston-based private equity investor, for $550 million in cash and debt.

The deal appears to be the largest merger-and-acquisition transaction disclosed so far this year in Minnesota.

Summit Partners is buying out shareholders, including Minnetonka-based Lemhi Ventures, which invested $27 million with Boston-based Bain Capital Ventures in Ability in 2011. Ability management and Bain Capital are rolling over an unspecified amount of their investment in the company as minority shareholders.

"My goodness, we've seen such phenomenal growth and the customer response has been so strong," said Ability CEO Mark Briggs in an interview Thursday. "And to get this kind of validation from two of the leading private equity firms in the world … and the shareholders who are selling are exiting with a very nice return.

"This confirms the course we've been on for the past few years and validates the contribution to innovation and service Ability has brought to the health care industry. Providers need the very best clinical and administrative technology supporting their work in changing health care in this country for the better. We intend to continue as leaders in that transformation."

Briggs, who joined the company in 2010, declined to quantify Ability's revenue other than to say it's experienced double-digit revenue growth. The company, based in Butler Square in the Warehouse District, has doubled employment to more than 220 employees in the past four years, including satellite offices in Boston, Cincinnati and Tampa, Fla.

Ability, working with medical providers and the federal Medicare program, has developed software that has streamlined the payment network from Medicare to providers, hospitals, clinics and home health agencies in what Ability says is now the country's largest, secure Web-based payment-and-information exchange in the country.

"Ability's phenomenal growth proves they are delivering innovations that truly respond to the needs of the health care industry," Darren Black, a managing director of Summit Partners said in a prepared statement. "We look forward to helping them take their exciting vision to a new level."

Summit Partners, which has raised nearly $15 billion in capital since 1984, said the $550 million Ability deal is one of its largest ever.

Briggs said the additional investment by Summit Partners will allow for continued development of the Medicare-standardized payment portal, which he said has markedly reduced paperwork and duplication and has the added benefit of allowing "care providers to have a complete view of their patients' information, which ultimately leads to better care" as well as greater economy.

In addition to the 2011 investment in Ability by Bain Capital and Lemhi of $27 million, Ability previously had raised about $16 million in equity when it was known as VisionShare.

"This transaction is great validation of the enthusiasm and support we have had for many years for Ability's vision and we congratulate the ­Ability team on terrific execution," said Tony Miller, managing partner of Lemhi Ventures.

Dan Carr, CEO of the Collaborative, which brings together entrepreneurs and financiers, said the Ability acquisition is validation of "a Minnesota innovator that's grown leaps and bounds in the past several years. Mark Briggs … and team have done a great job in this hard-to-handle health care IT sector. The sheer size of the financing is notable, but it is also exciting that Ability will continue to grow, innovate and employ folks.

"Kudos to the team at Ability, to their venture partners … and all the way back to their angel investors who helped early in their start-up. A great entrepreneurial, job-creating Minnesota success."

The deal is expected to close shortly, subject to regulatory approvals.