Before deficit cutters look to cut programs or raise Americans' taxes, they should probably look to dipping into one untapped resource: back taxes owed to the government by its own employees.

According to an IRS study conducted last year, government employees and federal retirees owe Uncle Sam more than $3.3 billion in delinquent tax payments. Among the worst offenders were hundreds of thousands of employees of the U.S. Postal Service owe more than $280 million.

The biggest group, though, is reportedly retired military personnel who owe more than $1.5 billion.

CNBC also notes that a number of White House employees are behind on their taxes -- employees in the executive office of the president owe more than $831,000.