Tax credits went to families that didn't qualify, unemployment benefits went to people who had jobs and medical payments were made for treatments that might not have been necessary.
Congressional investigators say the figure could be even higher.
The Obama administration has reduced the amount of improper payments since they peaked in 2010. Still, estimates from federal agencies show that some are wasting big money at a time when Congress is squeezing their budgets.
The improper payments include overpayments, underpayments, payments to the wrong recipient and payments made without proper documentation.
A House Oversight subcommittee is holding a hearing on the issue Wednesday afternoon.