Centene Corp. has named a new top lawyer in the wake of the global health care firm’s $17 billion acquisition of WellCare Health Plans Inc.

The St. Louis-based firm announced on Monday that senior vice president Chris Koster will take over as general counsel and secretary on Feb. 19. The Fortune 100 company’s former GC, Keith Williamson, has been tapped to serve as president of the Centene Charitable Foundation, the company’s philanthropic arm.