More than 70,000 veterans disability claims are currently backlogged in Veterans Affairs processing centers, seven months after department officials missed their public goal of getting the number down to zero.

VA Acting Under Secretary for Benefits Thomas Murphy said that figure includes a substantial number of claims left open longer than four months intentionally to ensure veterans are receiving all of the payouts they deserve. But he acknowledged his agency needs to drive that number down further.

"This is still a continuous improvement process for us," he said. "We are not satisfied with the number now, and we won't be satisfied until we are much closer to zero."

Roughly one in five benefits claims submitted to the Veterans Benefits Administration ends up taking longer than four months to process, the department's long-held promise for processing the cases. That does not include appeals cases, which follow a different process and often take years to resolve.

That ratio and the total number of backlogged cases have remained steady since last fall, when department officials announced they would not reach the goal of zeroing out the backlog by the end of 2015.

The goal of eliminating the backlog was announced by President Barack Obama and VA leaders in 2009, part of an ambitious push for service improvements . As recently as three years ago, the backlog total topped 610,000 cases, causing an outcry from veterans and lawmakers frustrated with waits in some instances topping a year.

New electronic records systems and mandatory overtime for claims processors drew down the backlog by almost 90 percent over two years, but pulling it down even further has proven difficult.

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Murphy said three years of mandatory overtime for processors ended in December, although voluntary overtime hours are still being used to keep daily workloads at between 4,500 and 5,200 cases a day.

The department also recently launched a new national work queue which allows employees across the country to help regional offices seeing spikes in filings, electronically moving that extra work across state lines to more quickly process the case load.

But department officials expect another record-breaking year for case filings in fiscal 2016, adding to the workload despite the processing improvements.

"That's the new norm for us," Murphy said. "We're dealing with a volume and complexity of cases that's growing every year."

In the late 1990s, most veterans applying for claims received a disability rating around 30 percent. Today that number is close to 50 percent, reflecting the expanding list of illnesses and injuries eligible for compensation.

The number of veterans receiving some form of disability compensation from VA rose from 2.3 million in 2001 to around 4.2 million last year.

At least part of the remaining backlog is attributable to cases where veterans update their claim late in the process with new medical information or conditions, requiring extra processing time.

Murphy could not give a specific breakdown, but said he believes a substantial amount of the roughly 70,000 remaining cases fall into that category of veterans who need more than 125 days to have their cases properly handled.

Still, he said, "our challenge is to identify why some other [cases] do not finish in 125 days, and how do we address that."

Leo Shane III covers Congress, Veterans Affairs and the White House for Military Times. He can be reached at lshane@militarytimes.com.