WASHINGTON - Kerry N. Weems, a longtime federal health official, is President Bush's choice to oversee the Medicare and Medicaid programs.

If confirmed by the Senate, Weems would succeed Mark McClellan, who resigned in October. Weems is deputy chief of staff to Health and Human Services Secretary Mike Leavitt.

The Centers for Medicare and Medicaid Services oversees federal health programs for the elderly, disabled and the poor. It accounts for about a fifth of all federal spending.

The president is also nominating Tevi David Troy to be deputy secretary at HHS. Troy is the deputy assistant to the president for domestic policy.

Leavitt said yesterday, "Both bring a broad array of knowledge, management experience and expertise that will enhance our ability to advance effective policies to improve Americans' health."

Medicaid provides health coverage and services to nearly 53 million low-income people. Medicare provides coverage for about 43 million elderly and disabled people.

Weems has been one of Leavitt's most trusted advisers on budget issues as the administration tries to restrain the pace of health spending. Still, it's unusual for a career federal employee to be nominated for such a top political appointment.

But former Deputy HHS Secretary Alex Azar said Weems would be well-positioned to run the agency.

"If you're looking for somebody who knows the programs inside and out, and knows also how to get things done in the government with no transition period, he's it," Azar said. "He's been at the center of all that."

Leslie Norwalk has been the acting CMS administrator since McClellan left. She said she was not ready to commit to staying through Bush's second term, and indicated to Leavitt early on that she did not want to be considered for the job.

Troy had primary responsibility for debate preparation in Bush's reelection campaign. He also has been Bush's liaison to the Jewish community.