The way the government rates service members' disabilities is inconsistent, and the Army might be shortchanging injured soldiers, the chairman of a special commission said Thursday.

Testifying before a Senate panel, retired Lt. Gen. James Terry Scott, chairman of the Veterans' Disability Benefits Commission, detailed problems in the Pentagon and Veterans Affairs ratings systems. Critics contend the ratings are easily manipulated to limit disability payments and create undue confusion in a claims system already strained to the limit.

"It is apparent that service members are not well served," Scott said in testimony prepared for delivery to an unusual joint hearing of the Senate Armed Services and Veterans Affairs committees called to examine gaps in the system.

In a preliminary review of Pentagon and VA data, the commission found the Army was much more likely than the other active forces to assign a disability rating of less than 30 percent, the typical cutoff to determine whether a person can get lifetime retirement payments and health care.

VA ratings tended to be higher, due to a separate system the department used that gave consideration to whether injured veterans were afflicted with multiple disabilities — not just a predominant one.

While the differing standards account for some inconsistencies, "it is also apparent that DOD has strong incentive to assign ratings less than 30 percent so that only separation pay is required," Scott said in testimony. His commission was formed in 2004 to study ways to improve the benefits system and is scheduled to issue a report later this year.

Scott also faulted the failure of the Pentagon and VA to work more effectively to create a shared electronic system for health records. He said his commission had repeatedly gotten vague, misleading or outright inaccurate explanations from the departments.

The Senate hearing is the latest to examine troop care after disclosures in February of shoddy conditions and outpatient treatment at Walter Reed Army Medical Center, one of the premier facilities for treating injured service members from Iraq and Afghanistan.

Among the complaints are the difficulties troops and veterans have in navigating the health care system, including long waits, lost paperwork and subjective ratings as they move from military hospitals to the VA's vast network of 1,400 clinics and treatment facilities.

The Army has acknowledged that it must improve its disability ratings system, and the Pentagon and VA have pledged to work together, most recently touting plans to share inpatient records in one system.

"A full solution is still several years away," Deputy Defense Secretary Gordon England said in prepared testimony, while offering assurances that he and VA Secretary Jim Nicholson do confer "when issues need to be addressed at our level."

Since the Walter Reed controversy, three high-level Pentagon officials have been forced to step down, including former Army Secretary Francis Harvey and Maj. Gen. George W. Weightman and Lt. Gen. Kevin Kiley, the two previous commanders at Walter Reed.

An independent review group appointed by Defense Secretary Robert Gates this week said that money woes and Pentagon neglect were to blame for many of the problems, concluding that "leadership at Walter Reed should have been aware of poor living conditions and administrative hurdles" but chose to ignore them.

But on Thursday, acting Army Secretary Pete Geren expressed confidence in the new leadership at Walter Reed. He said numerous steps have been taken to improve conditions, such as adding more case managers, setting up phone hot lines and reducing paperwork.

"We are under no illusions that the work ahead will be easy or quick — or cheap; we have a lot to do to get this right," Geren said. "Mending the seams and fixing the myriad issues we have recently uncovered will take energy, patience, determination and above all, political will."