WASHINGTON (AP) - President Barack Obama bypassed the Senate Wednesday and appointed Dr. Donald Berwick, a Harvard professor and patient care specialist, to run Medicare and Medicaid.

The decision to use a so-called recess appointment to install Berwick as administrator of the Centers for Medicare and Medicaid Services drew immediate fire from the GOP. Republicans have raised concerns about Berwick's views on rationing of care and other matters and said it was wrong for Obama to go around the normal Senate confirmation process. That view was echoed by a key Democratic committee chairman, although the recess appointment is a tool used by presidents of both parties.

Berwick has wide support in the medical community but some Democrats feared the GOP would use his confirmation hearings as an opportunity to reopen last year's divisive health care debate. Obama defended the decision to appoint Berwick and two other officials, one to a pension board and the other to a White House science post.

"It's unfortunate that at a time when our nation is facing enormous challenges, many in Congress have decided to delay critical nominations for political purposes," Obama said. "These recess appointments will allow three extremely qualified candidates to get to work on behalf of the American people right away."

Senate Minority Leader Mitch McConnell accused Obama of trying to "arrogantly circumvent the American people" with Congress out of town for its annual July Fourth break. Berwick could serve through next year without Senate confirmation.

Senate Finance Chairman Max Baucus, D-Mont., whose committee would have held Berwick's confirmation hearing, also said he was troubled by the recess appointment.

Berwick, 63, is a pediatrician, Harvard University professor and leader of a health care think tank, the Institute for Healthcare Improvement, that works to develop and implement concepts for improving patient care. The programs he will oversee - Medicare and Medicaid for the elderly, poor and disabled, along with the Children's Health Insurance Program - provide care to about 100 million people, or around 1 in 3 Americans.