AP – April 12, 2011: Medicare and Medicaid Administrator Donald Berwick gestures during an interview with The Associated Press in Washington.

WASHINGTON –  Medicare chief Don Berwick, the point man for carrying out President Obama’s health care law, announced Wednesday that he will step down on Dec. 2 in anticipation of not getting confirmation in the Senate to extend his term beyond a recess appointment.

Medicare chief Don Berwick, a Harvard professor widely respected for his ideas on how to improve the health care system, became the most prominent casualty of the political wars over a health care overhaul law whose constitutionality will be now decided by the Supreme Court.

Berwick’s Dec. 2 resignation was confirmed by a senior congressional official, speaking on condition of anonymity ahead of an announcement by the administration. He will be replaced by his principal deputy, Marilyn Tavenner, formerly Virginia’s top health care official.

Forty-two GOP senators — more than enough to derail Berwick’s confirmation — had announced their opposition to his nomination months ago. That started a countdown on his temporary appointment, scheduled to run out at the end of the year.

Berwick’s statements as an academic praising Britain’s government-run health care had become a source of controversy in politically polarized Washington. Although he later told Congress that “the American system needs its own solution” and Britain’s shouldn’t be copied here, his critics were not swayed.

A pediatrician before becoming a Harvard professor, Berwick has many admirers in the medical community, including some former Republican administrators of Medicare. His self-styled “triple aim” for the health care system includes providing a better overall experience for individual patients, improving the health of groups of people such as seniors and African-Americans, and lowering costs through efficiency.

But some of his professorial ruminations dogged him in Washington. Republicans accused him of advocating health care rationing, which Berwick denies.

As Medicare chief, Berwick oversaw the drafting and rollout of major regulations that will begin to reshape the health care system, steering Medicare away from paying for sheer volume of services and procedures and instead putting a premium on quality care that keeps patients healthier and avoids costly hospitalizations.

Berwick turned 65 this year, making him the first Medicare chief eligible to be enrolled in the program. He told The Associated Press he was putting in his application, but that he intends to keep working to improve the nation’s health care system.