HealthSpring plans to create the seventh largest Medicare Advantage plan through its acquisition of Baltimore, Md.-based Bravo Health.

Nashville, Tenn.-based HealthSpring will acquire Bravo Health, a privately held company, for $545.0 million, adding more than 100,000 Medicare Advantage and 290,000 Part D Prescription Plan members to its rolls. The deal is expected to close by the end of the year.

The deal is the latest is a series of efforts by companies to form new relationships in the face of federal health care reform.

“With diversified geography and increased membership scale, the combined companies will be even better positioned in the new environment created by health insurance reform,” Herb Fritch, chairman and chief executive of HealthSpring, said in a statement.

Bravo Health is an operator of Medicare Advantage coordinated care plans in Pennsylvania, the Mid-Atlantic region, and Texas, and Medicare Part D stand-alone prescription drug plans in 43 states.

“I cannot think of a better way to demonstrate our commitment to Medicare Advantage and our confidence in the long-term future of the program than the transaction we are announcing,” Fritch said. “This acquisition will extend HealthSpring’s reach into new geographies, including an immediate and sizable presence in the Philadelphia market.”

Fritch said the transaction will create the largest company in the country focusing exclusively on the Medicare Advantage population. The prescription plan will be the ninth largest in the U.S., he said.

Jeff Folick, chairman and chief executive of Bravo Health, said the acquisition is “the right next step for our company, and we are fortunate to be aligning ourselves with an organization that is so similar to ours.”

Bravo Health generated premium revenue of about $832.8 million in the first six months of this year.

Bravo Health, based in the Brewers Hill area of Baltimore City, is not expected to leave those offices, according to a report in the Baltimore Business Journal, which also indicated that the company has been adding up to 40 jobs a month to meet its growing membership’s needs.

Founded in 1996, Bravo Health’s licensed subsidiaries provide Medicare beneficiaries access in Delaware, Maryland, New Jersey, Pennsylvania, Texas, and Washington, D.C. and offer Part D Prescription Drug Plans in 43 states.

HealthSpring owns and operates Medicare Advantage plans in Alabama, Florida, Georgia, Illinois, Mississippi, Tennessee, and Texas and also offers a national stand-alone Medicare prescription drug plan.