Magellan Health Services Inc. will have a new chief executive at the start of the year as current CEO René Lerer steps down to become a full-time executive chairman.

The change is part of a transition to take place over several years. Barry M. Smith will be the new CEO starting Jan. 1. Smith is a member of the company's board.

Lerer will serve as executive chair all of next year, and he will become a "non-executive chair" in 2014. He might stay on as non-executive chairman for an additional year.

"Barry Smith is a recognized health care industry leader with a track record of success and someone who has a deep understanding of Magellan having served on our board," Lerer said. "He is the right person to lead Magellan into the next phase of our transformation. I'm looking forward to my new role as executive chairman, and working in partnership with Barry."

Smith has been operating partner for Health Evolution Partners since 2011, investing in various health care businesses. He was founder, chair and CEO of VistaCare, chair and CEO of ValueRx, and he held senior positions in PCS Inc. and Baxter International. Smith was on Magellan's board from 2005 through 2008. He joined again in 2011.

He is lead director of CenseoHealth, chair of Optimal Radiology and lead director of Halcyon Health Services.

Avon-based Magellan is a specialty health care management company that specializes in behavioral health, radiology and specialty pharmaceuticals. The company manages healthcare benefits for employers and government agencies with 33.8 million customers in behavior health, 17.3 million in radiology benefits and 8 million customers in pharmacy programs.