During FY 2009, the GAO reported that the U.S. government incurred approximately $683 billion in expenses for the Department of Defense (DoD) and $54 billion for Homeland Security, a total of $737 billion. The GAO financial statements present data on an accrual basis, meaning as expenses are incurred rather than actual cash payments.GAO-2009 Financial Statements of the U.S. Government – Page 45
