Without opposition, the House passed legislation Wednesday that aims to improve the care of wounded soldiers returning from Iraq and Afghanistan.

The bill (HR 1538) is Congress’ initial response to problems reported in the military’s overburdened medical bureaucracy, especially at Walter Reed Army Medical Center in Washington, D.C.

Passed on a roll call vote of 426-0, the bill would add caseworkers and counselors to the military’s medical system and force the Pentagon and Veterans Affairs Department to better coordinate the transfer of service members between the two bureaucracies.

More than 25,000 servicemembers have been wounded in Iraq and Afghanistan, according to the Pentagon. Veterans groups have reported that many wounded soldiers have complained that the military provides improper or inadequate care.

The VA has come under fire as well, particularly for providing inadequate screenings and care for head wounds, which have become the signature injury in the two wars.

“There is no doubt that the military medical system has been overwhelmed in meeting the demands of war over the past four years,” Armed Services Chairman Ike Skelton, D-Mo., said Wednesday.

There is no Senate version of the bill. But Barack Obama, D-Ill., and Claire McCaskill, D-Mo., have offered an amendment to a war spending bill (HR 1591) that the Senate is considering this week.

Their amendment would add caseworkers and mental health counselors to military hospitals and provide money for the military to develop a system to allow soldiers to submit medical paperwork over the Internet. It is not clear whether the Senate will consider the amendment.

The White House has said President Bush generally supports the legislation, although it called the bill “premature” in a statement issued Tuesday.

Bush has appointed a commission to report on problems in the military medical system. In its statement, the administration said it would prefer that Congress wait until the commission’s report — due by July 31 — to write legislation.

Implementing the legislation could cost “billions of dollars,” according to the Congressional Budget Office (CBO). That is because one provision of the measure orders the Defense Department and the VA to create a common medical information system, to more easily transfer files from one agency to the other.

CBO said that it was unable to specify the cost of such a system because the two departments are not sure how they would create it. But building a new computer system from the ground up would be hugely expensive, CBO said.

A less expensive alternative would be for the Pentagon and VA to improve their current systems enough to comply with the legislation.

Aside from a new computer system, the bill would cost about $300 million over the next five years, CBO said.

The military has received criticism from both Democrats and Republicans over conditions at Walter Reed, and the debate Wednesday reflected those bipartisan concerns. Some Democrats, though, suggested that the Bush administration had fallen short of truly supporting the troops.

“Supporting our troops does not mean that you simply salute as you send them off to war,” said Kathy Castor, D-Fla. “It also means that they are supported when they come home, their families are respected, and our wounded warriors receive superior health care for their physical injuries and mental scars.”

The House adopted 12 amendments to the measure, all of them uncontroversial, mostly minor adjustments or requests for studies.

All amendments were adopted on voice votes, except a measure by Joe Sestak, D-Pa., and Patrick J. Kennedy, D-R.I., that would order the Defense Department to research Post-Traumatic Stress Disorder and develop a plan to prevent soldiers from suffering from the syndrome. The amendment was adopted, 426-0.

Other notable amendments include:

• A measure by John Barrow, D-Ga., that would require the government to reimburse disabled veterans for their travel to and from VA offices at the same rate paid to government employees. The reimbursement rate for veterans — 11 cents per mile — has not been increased since 1977, Barrow said. Government employees are paid 48.5 cents per mile.

• A measure by John Kline, R-Minn., that would dedicate $10 million from a $50 million fund created in the bill to the Marines’ Wounded Warrior Regiment, which monitors wounded active-duty Marines who are in “outpatient status.” The bill would create a similar unit within the Army, to exist for at least a year.