While she waited for approval, Henline said Sorbello dropped from 132 pounds to 88, and her list of ailments grew to include abnormal blood leakage in her heart, muscle atrophy, seizures and extreme fatigue. She died on June 25, 2010, at age 52.

After her death, Henline said the agency came after him to collect more than $14,000 in benefits paid to Sorbello's son, Stephen Hunt, whom Henline continued to raise. The agency claimed it was an overpayment, and Henline went back to court to settle the dispute. An administrative law judged ruled in his favor in June. His attorney, Mering, represented him pro bono on that case.

"It's been six years that I have fighting with these people," Henline said. "You're not only dealing with Social Security, but all of the hospital issues, the billing department issues and the financial issues."

On top of that, Henline said he had to bury his wife.

"She was the bravest person I have ever known," he said.

Sen. Tom Coburn, an Oklahoma Republican and ranking member of the Senate subcommittee on investigations, said at a recent hearing that the Social Security Administration is on a precipice. He said oversight by Congress — especially to ensure the agency's long-term solvency — is critical.

"The flood of Social Security disability applications over the past few years has tested the agency's resources and personnel," Coburn said. "As a result, disabled Americans are waiting longer and longer before receiving the benefits they deserve."

Coburn's panel in September revealed the results of an 18-month investigation that found administrative law judges overturned agency decisions to award benefits despite insufficient or incomplete evidence in more than a quarter of 300 cases.

One judge wrote "etc., etc., etc." in case files rather than explain the decision, and some held perfunctory hearings that lasted less than five minutes, according to the subcommittee. Senators raised concerns that people with questionable claims were getting disability payments, depleting the Social Security trust fund.

On the flip side, claimants and their lawyers raised concerns that some administrative law judges were denying benefits to deserving workers. The rates at which judges approve claims vary wildly across the nation.

In Dallas, Judge Gilbert Rodriguez had a 5.28 percent approval rating for cases in which he issued decisions from October 2011 to August 2012. That's compared to a 99.35 percent approval rating by Judge Gerald I. Krafsur in Kingsport, Tenn. Rodriguez issued 303 decisions to Krafsur's 468.

Judge Randall Frye, president of the Association of Administrative Law Judges, said the circumstances of cases heard by an individual judge affect approval ratings. For example, missing medical records led to denials for many Gulf Coast claimants after Hurricane Katrina devastated the region in 2005.

"Disability judges work to protect the Treasury as well as to insure that every claimant gets a fair hearing," Frye said in a statement.

Jonas, who runs the agency's appellate operations, said improvements have been made in recent years, yielding "quicker, higher quality disability decisions." She noted that the decisions among judges are becoming more consistent. Since 2007, the number of judges who grant awards in more than 85 percent of cases has dropped by two-thirds.

She also said wait times for hearings are shorter. The agency began using video conferencing to alleviate scheduling conflicts, simplified regulations and established productivity expectations for administrative law judges to help eliminate the backlog of old cases, Jonas said. And the agency has nearly doubled the number of judges over the past two decades.

But the caseload continues to balloon. In 1992, an average of 826 judges issued more than 356,700 hearing decisions. This year, more than 1,500 judges are expected to complete more than 800,000 cases.

"The Supreme Court has recognized that we are 'probably the largest adjudicative agency in the Western world,' and we take very seriously our responsibility to issue timely and accurate decisions," Jonas told the senators at the recent hearing. "Of course, opportunities for continued improvement remain."

Prolonged legal battle

Nicholas applied for disability in August 2003, shortly after he blacked out in his living room and fell head-first onto his coffee table. He was hospitalized for a month, underwent heart valve surgery and had a pacemaker implanted.

By the time his lawyer called this year to tell him his fight against the Social Security Administration was successful, Nicholas was back in the hospital. He figured he had lost the case and expected to hear condolences from his lawyer.