summary is here. The summary includes a link to the full report.
For FY 2015 three big U.S. agencies–the Department of Defense, Department of Housing and Urban Development, and the Department of Agriculture–failed to get clean opinions. Their accounts had "material weaknesses". Last year (FY 2014), by contrast, almost all of the key federal agencies received clean audit opinions.
In addition, the GAO highlighted the following risks:
Pension Benefit Guaranty Corporation (PBGC) liabilities exceeded its assets by more than $76 billion as of the end of FY 2015.
Fannie Mae and Freddie Mac reported maximum remaining contractual commitment to the GSEs, if needed, is $258.1 billion.
U.S. Postal Service has reached its borrowing limit of $15 billion and finished FY 2015 with a reported net loss of $5.1 billion.
Wall Street on Parade comments that people who think that Donald Trump will clean up this mess should take a look at his own financial reporting as required under campaign finance laws.