Addressing improper payments, better managing IT acquisition, addressing cybersecurity challenges, disposing of unneeded facilities and better managing vehicle fleets were the top priorities on GAO’s list during a recent hearing on improving government efficiency and effectiveness.

GAO’s testimony before the Senate Budget Committee to an extent recapped its series of audits in those areas, including its high-risk list and its most recent report on overlap and duplication among agencies.

It said that since 2003 when the government started tracking improper payments, a total of $1.2 trillion has been reported–and despite attention to the issue, the estimate grew by $7 billion in 2016 over 2015 to $144 billion. Of that, an estimated 93 percent is overpayments, it added, naming Medicare, Medicaid and the earned income tax credit as accounting for about three-quarters of the total.

It said that management challenges in that area include that some programs do not report improper payment estimates at all and that some of those that are reported are unreliable due to accounting deficiencies.

On IT, GAO said that agencies continue to spend most of their budgets maintaining legacy systems, some of which have components as much as 50 years old and are vulnerable to hacking. It said that agencies similarly continue to spend money on maintaining unneeded properties, due in part to a complex process for disposing of them, and on operating an excessive number of vehicles, since agencies commonly either lack criteria for deciding a proper number or don’t follow through on their own findings that they have an excess.