<Tr> <Td> Unified Medical Budget </Td> <Td> 48.8 </Td> </Tr> <P> The role of support service contractors has increased since 2001 and in 2007 payments for contractor services exceeded investments in equipment for the armed forces for the first time . In the 2010 budget, the support service contractors will be reduced from the current 39 percent of the workforce down to the pre-2001 level of 26 percent . In a Pentagon review of January 2011, service contractors were found to be "increasingly unaffordable ." </P> <P> The U.S. Department of Defense budget accounted in fiscal year 2010 for about 19% of the United States federal budgeted expenditures and 28% of estimated tax revenues . Including non-DOD expenditures, military spending was approximately 28--38% of budgeted expenditures and 42--57% of estimated tax revenues . According to the Congressional Budget Office, defense spending grew 9% annually on average from fiscal year 2000--2009 . </P> <P> Because of constitutional limitations, military funding is appropriated in a discretionary spending account . (Such accounts permit government planners to have more flexibility to change spending each year, as opposed to mandatory spending accounts that mandate spending on programs in accordance with the law, outside of the budgetary process .) In recent years, discretionary spending as a whole has amounted to about one - third of total federal outlays . Department of Defense spending's share of discretionary spending was 50.5% in 2003, and has risen to between 53% and 54% in recent years . </P>

Us defense budget as percentage of total spending