In a rush to cut a huge backlog of claims for disability benefits, the Department of Veterans Affairs is making payments to tens of thousands of veterans without adequate medical evidence that they deserve the benefits, the department’s inspector general’s office said Monday.

Without improvements, the VA could make unsupported payments to veterans of about $371 million over the next five years for claims of 100 percent disability alone, said Linda Halliday, an assistant inspector general.

The IG’s office also found widespread problems at VA regional offices in Philadelphia and Baltimore, including mail bins full of disability claims and associated evidence that had not been electronically scanned for three years.

Spot inspections revealed that VA also made errors in one in four claims involving traumatic brain injury, Halliday told the House Veterans Affairs Committee in prepared testimony.

“Improved financial stewardship at the agency is needed,” Halliday said. “More attention is critical to minimize the financial risk of making inaccurate benefit payments.”

Special initiatives designed to remove older claims and speed processing of new claims are worthwhile, Halliday said, but in some cases they “have had an adverse impact on other workload areas such as appeals management and benefits reductions.”

The VA used the hearing to claim “tremendous progress” in reducing a disability claims backlog that reached about 611,000 in March 2013. The backlog is now about 275,000 — a 55 percent decrease from the peak, said Allison Hickey, undersecretary for benefits at the VA.

Last year, the Veterans Benefits Administration completed a record 1.2 million disability rating claims, Hickey said, and the agency is on track to complete more than 1.3 million rating claims this year. More than 90 percent of the claims are being processed electronically, she said.

The VA has set a goal to process all claims within 125 days at 98 percent accuracy in 2015, but so far has fallen far short. The VA now processes most claims within 154 days at a 90 percent accuracy rate, compared with an accuracy rate of 86 percent three years ago, Hickey said. At one point, veterans were forced to wait an average nine to 10 months for their disability claims to be processed.

Hickey said the department has spent the past four years redesigning and streamlining the way it delivers benefits and services.

Halliday, however, said her investigators have found numerous problems in handling VA benefits, including faulty claims processing that “increases the risk of improper payments to veterans and their families.”

The VA has long struggled to cope with disability claims. The backlog had intensified in recent years as more solders returned from Iraq and Afghanistan, and as the VA made it easier for Vietnam-era veterans to get disability compensation stemming from exposure to Agent Orange.

Lawmakers in both parties have complained about the Obama administration’s handling of the problem, and some have called for an independent commission to address it.