A recent Postal Service audit showed that employees worked nearly 2.3 billion hours for fiscal years 2010 and 2011, National Journal reports.
Hours unapproved by managers and supervisors in that same timeframe add up to around $717 million in unauthorized overtime pay, auditors found.
The audit said managers are responsible for reviewing and approving overtime but many employees told auditors that managers never brought up the issue, according to National Journal.
Last year, the U.S. Postal Service lost $5.1 billion and lawmakers are working to revamp the Postal Service’s business model in an effort to cut costs.
That loss would have totaled $10.6 billion due to a mandated payment of $5.5 billion for retiree health benefits if not suspended by Congress.
Lawmakers are considering the implementation of a control-board like agency for the Postal Service’s budgetary concerns, which legislators say could save around $20 billion in the coming years.