The Defense Department plans to transfer thousands of uniformed health care personnel out of their positions in military medical facilities over the next few years and replace them with civilian workers or contractors.

The initiative is part of a larger Pentagon effort to reassign military members to jobs that are more directly tied to war-fighting and national security, leaving the tasks they had been performing to civil servants or private contractors, or eliminating the positions.

The plan could bring important changes in the way the Defense Health Program provides medical and dental care to 8.9 million active members of the military, their dependents and military retirees. The changes are expected to affect thousands of doctors, dentists, nurses, administrators and ancillary staff employed in a network of 75 military hospitals and 461 military clinics.

What will not change, officials contend, is the quality and level of care provided in a system that employs 40,648 civilians and 91,917 military members, with a current budget of $17.3 billion.

Pentagon officials declined to discuss most details of the plan, saying it is part of the department's budget-development process. The administration has requested $17.6 billion for the department's health program next year, including $35.8 million to fund the conversion of positions held by military personnel to civilian workers or private contractors.

The rationale behind the plan is that only certain jobs -- for instance, those of surgeons who care for Marines wounded in battle -- must be performed by a person in uniform, officials said. Others can be done by civilian or contract workers -- or could be eliminated.

"Generally speaking, should a position be converted from military to civilian, the military personnel would be reassigned to another position in military medicine that requires a military person with that expertise," Marianne Coates, a Defense spokeswoman, said in an e-mail response to questions. "Importantly, the military's health plan, Tricare, has tremendous flexibility designed in so that our beneficiaries continue to receive the care they need, when they need it. . . . We have civilian physicians and nurses working in our military medical facilities today, so having more would not degrade our standard of care."

Navy Lt. Cmdr. Tim Weber, division director for manpower operations at the Navy's Bureau of Medicine, elaborated on how the planned changes are expected to play out in one branch of the military's medical facilities.

Under the plan, a uniformed pediatrician at, say, Naval Hospital Jacksonville in Jacksonville, Fla., might be replaced by a civilian doctor or private contractor, Weber said. The same might be true of a Navy nurse or uniformed administrator who works at the San Diego Naval Medical Center.

As many as 5,415 jobs now held by uniformed Navy members will be switched to contractors or civilians by fiscal 2011, including 1,772 positions over the fiscal year that begins Oct. 1, he said. The affected personnel will transfer to a "military essential" position when their rotation in their current post ends.

"They will continue in their military careers," Weber said. "We are not involuntarily reducing our numbers. . . . Navy medicine globally is slightly understaffed at the moment."

Weber said the plan is expected to save money in the long run by reducing the number of uniformed military health care workers, which in turn will reduce the Navy's retirement and infrastructure obligations. Officials also believe some of the positions being converted can be done more cheaply by civilians than by military members, he said.

Weber said the plan will not affect the 10,500 doctors, nurses and health care support staff members who travel with the Navy and Marines every day and provide direct care for them in battle. Nor will it change the jobs of the 24,000 health care workers in Navy hospitals in the United States who are part of a readiness group that can be deployed to hospital ships and fleet hospitals on short notice to support military missions, he said.

Navy Lt. Cmdr. Chito Peppler, a spokesman for the National Naval Medical Center in Bethesda, said officials there will not know how many people will be affected by the conversion plan until October.

Jim Yonts, executive director of the Association of Military Osteopathic Physicians and Surgeons, said the group's members -- the majority of them uniformed military members -- have not been told how the plan will work.

"On paper, it sounds like it would certainly be workable and I'm not sure that it would necessarily have any negative impact on our members," he said.

Weber, the Navy official, said: "We will continue to provide outstanding health care. All we're doing is changing the flavor of the uniform."