Gary Cohen to lead health reform implementation office

California is among a handful of states that have taken the lead in setting up exchanges, which will function as one-stop shops for individuals and small businesses to compare and buy coverage. The law says each state should set up its own exchange, but directs the federal government to establish a fallback in any state that doesn't.

Cohen is a former aide to Rep. John Garamendi (D-Calif.) and has also worked for the California insurance department.

CCIIO is overseeing most of the Affordable Care Act implementation, including exchanges and new regulations on insurance companies.

Mike Hash, who has been leading the office on an interim basis, will remain in place as the director of HHS's Office of Health Reform.