HealthSpring Inc. announced Tuesday it has agreed to acquire all outstanding capital stock of America's Health Choice Medical Plans Inc., a Florida-licensed HMO that operates Medicare Advantage health plans.

America's Health Choice has 15,290 members in Florida, including 400 in Brevard County. It generated about $150 million in revenue in 2005.

Nashville, Tenn.-based HealthSpring (NYSE: HS) will pay $50 million in cash for America's Health Choice. The closing of the acquisition is expected in the late third quarter or fourth quarter of this year.

The deal must be approved by Florida insurance regulators and the Centers for Medicare and Medicaid Services. Prior to the closing of the deal, HealthSpring will manage America's Health Choice operations for a monthly management fee.

HealthSpring Inc. is a managed care organization that focuses primarily on the Medicare Advantage market. The company operates Medicare Advantage and Medicare prescription drug plans in Tennessee, Texas, Alabama, Illinois and Mississippi.