Spending that’s not dependent on an annual or multiyear appropriations bill. Most mandatory spending is associated with such entitlement programs as Social Security, Medicare and Medicaid. Other forms of mandatory spending — salaries of federal judges, for example — account for a relatively small share of federal spending.
Mandatory spending in fiscal 2010 was $1.91 trillion, or about 55 percent of total federal spending. Most of this was for Social Security ($701 billion), Medicare ($520 billion), Medicaid ($273 billion) and unemployment insurance ($159 billion).
See also: Discretionary spending