Lawyers have raked in more than $7.5 billion in fees from the federal Disability Insurance program since 2009, according to a Manhattan Institute report issued Friday. And that money has come directly out of the pockets of workers through the Social Security payroll tax.

The report, "Wheels of Fortune," finds that fees paid by the Social Security Administration to those representing disability applicants totaled $1.23 billion last year.

By October of this year, these fees had already topped $970 million.

The way the Social Security Disability Insurance (SSDI) program works is that, if a person secures legal representation while applying for benefits, and then qualifies for the program, the advocate gets a cut of the money.

The idea behind these payments — which are capped at $6,000 per enrollee — is to make sure that no one is denied disability benefits simply because they can't afford to navigate the system.

But as the Manhattan Institute report notes, lawyers have "found ways to exploit legal rules in disability statutes to their personal benefit." The paper highlights allegations of fraud, kickbacks and other schemes to get the maximum number of people on the disability rolls.

In addition, those who've been turned down twice by the program can appeal their denials to an administrative law judge, some of whom have a record of approving 90% or more of those appeals.

Not surprisingly, the amount of money lawyers collected in SSDI fees nearly tripled between 2001 and 2013.

At the same time, the number of workers on disability has been climbing at a rate far faster than people known to have disabilities.

Between 2002 and 2010, SSDI rolls shot up 48%, even though the number of actual working-age disabled climbed only 15%, according to Census Bureau data.

Almost half of the nearly 9 million workers collecting SSDI benefits had enrolled in the program in just the past five years.

Not surprisingly, SSDI's costs have exploded as well, with spending up 155% since 2000 — faster than other major entitlement programs. Social Security, for example, climbed 90% over those years; Medicare spending rose 153%; and Medicaid was up 125%, budget data show.

And at $140 billion, the federal government now spends more on disabled workers than it does on education, housing aid, and food stamps combined.

"Disability insurance has become more like permanent unemployment insurance or a general welfare program," notes Tad DeHaven of the Cato Institute.

To be sure, the extent to which aggressive fee-seeking attorneys are to blame for the sharp rise in the disability rolls isn't entirely clear.

But the promise of those fees, combined with looser eligibility rules and more generous disability benefits, has created the perfect entitlement storm.

Left unchecked, SSDI's trust fund will go bankrupt in 2016, forcing Congress to take some action to avoid a massive benefits cut. The disability boom also is draining funds from Medicare — since enrollees are eligible for that program after two years.

And it's dampening economic growth, because those who go on SSDI almost ever rejoin the workforce, thereby shrinking the available pool of labor.

Follow John Merline on Twitter: @IBD_JMerline