The latest official estimate on money lost through improper payments at the Defense Department stands at $1.1 billion. Given the scale of DoD’s budget, that’s actually not bad relatively speaking, especially compared against high-error programs. Medicare, for example, lost well over $40 billion to improper payments last year. On the other hand though, it turns out the Defense Department doesn’t actually know the scale of its improper payment problem, so the numbers it reports to OMB and Congress are likely suspect. In a new report, the Government Accountability Office finds pervasive weaknesses that keep DoD from accurately estimating its improper payments. Asif Khan, GAO’s director of Financial Management and Assurance Issues, joins In Depth with more.