Washington ? President Obama on Wednesday appointed health care expert Donald Berwick to administer the Centers for Medicare and Medicaid Services, bypassing the Senate confirmation process over strong objections from Republicans who oppose the choice.

Obama used a recess appointment to name Berwick, a 63-year-old pediatrician, Harvard University professor and head of a nonprofit health-care institute, to the post that oversees the $800 billion-a-year program that provides health care to the nation’s elderly, poor and disabled. He was nominated in April, but no confirmation hearing was scheduled. The appointment during a congressional recess allows him to serve through 2011 without Senate confirmation.

Obama also used recess appointments Wednesday to install Philip E. Coyle III as associate director for national security and international affairs at the White House Office of Science and Technology Policy and Joshua Gotbaum as director of the Pension Benefit Guaranty Corporation.

In a White House statement announcing the moves, Obama accused Senate Republicans of stalling dozens of his appointments for political ends.

“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.

But Republicans blasted the appointments, particularly that of Berwick, who they say supports the rationing of health care.