This book looks at the three broad categories of federal spending; discretionary spending, mandatory spending, and net interest. Mandatory spending includes federal government spending on entitlement programs and Food Stamps as well as other budget outlays controlled by laws other than appropriation acts. Entitlement programs such as Social Security and Medicare make up the bulk of mandatory spending. Discretionary spending is provided and controlled through appropriations acts. Mandatory spending accounts for over half of total federal spending and almost a ninth of gross domestic product (GDP). Those three programs, therefore, make up over 40% of federal spending. In the long term, projections suggest that if current policies remain unchanged, the U.S. faces a major fiscal imbalance, largely due to rising health care costs and impending Baby Boomer retirements.