The audit conducted by the Government Accounting Office found that TSA employees often received light punishments for misconduct ranging from allowing prohibited items past airport scanners to napping on the job, a GAO report said.
Some of the more serious violations the audit uncovered included allowing family members and friends to go through security without being screened, leaving work without permission and stealing.
Forty-seven percent of the cases the GAO analyzed resulted in letters of reprimand, 31 percent in suspensions and 17 percent in an employee being removed.
"While TSA has taken steps to help manage the investigations and adjudication process, additional procedures could help TSA better monitor the investigations and adjudications process," the GAO said.
It called on the agency to improve how it monitors allegations of misconduct and how it follows up after investigations.