As America's top CEO's push aggressively for austerity cutbacks in government programs that benefit ordinary citizens under the guise of the lobby group Fix the Debt, those same individuals are pocketing hundreds of millions in taxpayer subsidies, says a new report published Thursday.

The study, Fix The Debt CEOs Enjoy Taxpayer Subsidized Pay — by the Institute for Policy Studies and the Campaign for America's Future — reveals that thanks to a tax loophole which allows corporations to deduct unlimited amounts off their income taxes for the expense of executive stock options and other so-called “performance-based” pay, Fix the Debt member firms have raked in over a billion dollars of taxpayer-funded bonuses.

"The performance pay loophole serves as a critical subsidy for excessive compensation," says the report. "The larger the executive payout, the less the corporation pays in taxes. And average taxpayers wind up footing the bill."

According to the study:

During the three-year period 2009-2011, the 90 publicly held corporate members of the austerity-focused “Fix the Debt” lobby group shoveled out $6.3 billion in pay to their CEOs and next three highest-paid executives. These 90 Fix the Debt member firms raked in at least $953 million — and as much as $1.6 billion — from the “performance pay” loophole between 2009-2011. The exact full value of corporate windfalls from this loophole will remain impossible to compute until we have more complete mandated disclosure for executive compensation. Health insurance giant UnitedHealth Group enjoyed the biggest taxpayer subsidy for its CEO pay largesse. The nation’s largest HMO paid CEO Stephen Hemsley $199 million in total compensation between 2009 and 2011. Of this, at least $194 million went for fully deductible “performance pay.” That works out to a $68 million taxpayer subsidy to UnitedHealth Group – just for one individual CEO’s pay. A just-released proxy reveals that Hemsley pocketed another $28 million in “performance pay” in 2012, which computes into a tax break for UnitedHealth of nearly $10 million.

"Many of these executives have also added to America’s debt and deficit by using tax havens and other accounting tricks to have their corporations avoid paying their fair tax share," adds the report.

Reporting on the study, Huffington Post notes that the performance pay loophole "is extremely popular in corporate America." According to an earlier report by Citizens for Tax Justice, the exception allowed Fortune 500 companies to skip out on $11.2 billion in taxes in 2011.

"The stock option loophole is a major reason why corporations are paying record-low federal income tax rates," said Matthew Gardner, executive director of the Institute on Taxation and Economic Policy. "The worst of it is that there is no 'cost' to a corporation that uses stock options to pay its executives, so there's no justification for allowing them to deduct it as an expense. It's not an expense."