UnitedHealth Group subsidiary OptumHealth has purchased Brentwood-based Inspiris in a deal that closed last week.

Inspiris, founded in 1998, provides care and care management services to some 50,000 medically complex, chronically ill and elderly patients in Medicare, Medicaid and commercial insurance populations. Its acquisition, terms of which were not disclosed, should provide Inspiris with resources to expand its reach — Minneapolis-based OptumHealth serves some 60 million individuals and reported revenues of $5.8 billion last year.

“This agreement creates many opportunities for Inspiris, the patients we serve and our employees,” said Inspiris CEO Mike Tudeen in a written statement to NashvillePost.com. “By growing and gaining access to new resources, we will take the next step to reach more seniors and medically complex individuals and make a substantial difference in the care they receive.”

Founded in 1998 by former Healthways worker Jim Deal, Inspiris focuses on managing care for the roughly 10 percent of the population that drives the majority of medical costs.

OptumHealth — which provides health, financial and ancillary benefit services — is one of four reporting segments of UnitedHealth. In total, UnitedHealth (Ticker: UNH) recorded revenues of $94 billion in 2010 — OptumHealth was responsible for $610 million in earnings from operations that year and had the best operating margin of the company’s subsidiaries, at 10.4 percent.

(For perspective, local OptumHealth competitor Healthways reported 2010 revenue of $720 million and operating income of $90 million.)

Tudeen and the Inspiris management team will remain in place, and the company will maintain its Maryland Farms office.

UnitedHealth's purchase of Inspiris is its second big Williamson County deal in recent years. In 2009, the insurance giant paid more than $400 million for Franklin-based payment auditor AIM Healthcare.