Former members of the military like Mr. Bunn are being refused benefits at the highest rate since the system was created at the end of World War II, the report said. More than 125,000 Iraq and Afghanistan veterans have what are known as “bad paper” discharges that preclude them from receiving care, said the report, released Wednesday by the veterans advocacy group Swords to Plowshares.

The report for the first time compared 70 years of data from the Departments of Defense and Veterans Affairs. It found that veterans who served after 2001 were nearly twice as likely as those who served during Vietnam to be barred from benefits, and four times as likely as men and women who served during World War II.

“We separate people for misconduct that is actually a symptom of the very reason they need health care,” said Coco Culhane, a lawyer who works with veterans at the Urban Justice Center in New York.

About 6.5 percent of all Iraq and Afghanistan troops have bad paper discharges, the report said. The highest rate is found in the Marine Corps, where one in 10 is now ineligible for benefits.

“It has gotten worse with every generation, and it appears to hit the veterans Congress intended to protect,” said Bradford Adams, a lawyer and an author of the report. “They knew these folks had been through combat, and wanted to make sure they had help. The V.A. doesn’t seem to be doing that.”