The Defense Department, which has promised to publish a reliable account of how it spends its money by 2017, has discovered that its financial ledgers are in worse shape than expected and that it will have to spend billions of dollars in the coming years to make its financial accounting credible, the Center for Public Integrity reported Thursday.

The U.S. military has spent more than $6 billion to develop and deploy new financial systems, but the effort has been plagued by significant added overruns and delays, defense officials told the CPI, a nonprofit investigative news organization.

The Government Accountability Office said in a report last month that although the services can now fully track incoming appropriations, they still can’t demonstrate that their funds are being spent as they should be.