The military routinely rates wounded soldiers’ disabilities significantly lower than the Veterans Affairs Department does, prompting the chairman of a Senate panel to suggest Thursday that ratings should be left to the VA.

The government’s two systems for rating and treating veterans’ disabilities, which determine the amount of benefits they receive, were the subject of an unusual joint hearing of the Senate Armed Services and the Veterans’ Affairs committees Thursday.

Ret. Lt. Gen. James T. Scott, chairman of the Veterans’ Disability Benefits Commission, which is studying benefits for disabled veterans, told senators that the VA’s disability ratings are often higher than the military’s.

Wounded soldiers get an initial disability rating from the military that determines the amount of lifetime military benefits they will receive. They get a second rating when they are transferred to the VA for care after leaving military service.

A higher military disability rating would offer greater military benefits over a veteran’s life. Scott said it was possible that the Pentagon’s ratings are influenced by budget pressures.

“How can we, as a nation, ask our young men and women to serve and, when they are wounded while serving, put them in a position where they are ‘scared to death’ that we will not take proper care of them and their families?” asked Carl Levin of Michigan, quoting a wounded soldier he said he’d recently spoken with at Walter Reed Army Medical Center.

On the heels of revelations of problems at Walter Reed, lawmakers are scrutinizing the military health care system and the transition from military to VA care. For wounded military people and their families, the designated level of their disabilities has far-reaching implications.

Servicemembers that the military rates as being 30 percent or more disabled are eligible for military retirement benefits and lifetime health care for themselves and their families. Those rated less than 30 percent disabled receive only severance pay, and although they can receive health care from the VA system, their families cannot.

The Defense Department, Scott said, “has strong incentive to assign ratings less than 30 percent so that only separation pay is required and continuing family health care is not provided.”

Scott recommended that Congress give the VA sole responsibility for rating disabilities, prompting Levin to ask Deputy Defense Secretary Gordon England, “Why not do that?”

England agreed that the two rating systems are “confusing, and it’s particularly confusing for people who use the system.”

Levin, the chairman of Senate Armed Services, then interrupted: “Confusing? I think it’s unfair.” He asked England to answer his question within two weeks.

The Veterans’ Disability Benefits Commission was established by Congress in 2004. The commission recently analyzed the records of about 83,000 servicemembers who left the military between 2000 and 2006 because of disability.

Overall, the Pentagon rated 19 percent of the servicemembers as 30 percent or more disabled. In the Army, 13 percent of disabled soldiers made the 30 percent threshold. The Army also ruled that 27 percent of the soldiers included in the records the commission gathered were physically unfit for duty — but not officially disabled at all.

Yet the VA later ruled that those same soldiers were, on average, 56 percent disabled — a discrepancy that Scott said deserved an “in-depth analysis.”

Levin said the military’s 30 percent disability threshold looms large in the minds of wounded soldiers.

He noted that the House passed a bill March 28 (HR 1538) intended to increase the ranks of caseworkers and counselors in the military health system. It also would force the Pentagon and VA to make their medical information systems interoperable. Levin said his committee will address similar legislation soon.

After a series of news reports about inadequate and inappropriate care at military hospitals and in the VA system, lawmakers are intensely interested in the state of care for wounded veterans.

Presidential contenders John McCain, R-Ariz., and Democrats Hillary Rodham Clinton of New York and Barack Obama of Illinois attended parts of Thursday’s hearing, an indication of the subject’s political weight.

Two commissions — one appointed by Defense Secretary Robert M. Gates, the other by President Bush — are currently studying problems at Walter Reed and elsewhere in the military and VA health systems.

The commission Gates appointed, called the Independent Review Group, issued a draft report April 10, in which it said there is a “breakdown of health services and care management” when wounded servicemembers transfer from inpatient to outpatient status in the military’s health system. The commission has recommended a host of changes in the military’s medical procedures as well as increased spending for case managers in the military health system.