Mandatory vs. Discretionary Spending

Federal spending falls into three parts. Discretionary spending is the money Congress provides each year through the twelve appropriations bills, covering defense, agencies, and most grant programs. Mandatory spending, also called direct spending, flows automatically under permanent laws that set eligibility rules and benefit formulas, so it rises or falls with the number of people who qualify, without any annual vote. Net interest on the debt is paid automatically as well.

Of roughly seven trillion dollars in annual outlays, mandatory programs account for about sixty percent, led by Social Security at about 1.5 trillion dollars, Medicare at about one trillion, and Medicaid at about 600 billion, along with veterans' benefits, food assistance, refundable tax credits, and federal retirement. Net interest has grown to about 13 percent, now exceeding defense spending. Discretionary spending, about 1.8 trillion dollars, is roughly a quarter of the total and is split nearly evenly between defense and everything else, from the FBI and national parks to the NIH and air traffic control.

The split explains a recurring feature of budget politics: the annual appropriations battles, shutdowns, and spending caps involve only about a quarter of spending, while the programs driving long-term deficits grow on autopilot. Changing mandatory spending requires new legislation, usually through reconciliation, and because those programs reach tens of millions of voters, both parties are reluctant to cut them. Budget analysts across the spectrum agree that stabilizing the debt is arithmetically impossible through discretionary cuts alone.