Appropriations vs. authorization
The answer
Authorizing a program and funding it are two separate laws passed by two different sets of committees, and confusing them is one of the most common civic misunderstandings. An authorization bill creates or continues a federal program and can name a funding ceiling, "there are authorized to be appropriated $100 million." That sentence, even if signed into law, spends nothing. Only a separate appropriations act, passed by the Appropriations Committees, actually lets an agency draw money from the Treasury.1 A program can be fully authorized and still receive zero dollars.
How it actually works
Congress is supposed to authorize a program first, deciding whether it should exist and what it should do, then appropriate funds for it annually, deciding how much it actually gets, up to any authorized ceiling. Authorizing committees, Judiciary, Armed Services, Energy and Commerce, and so on, have subject-matter jurisdiction and write policy. The House and Senate Appropriations Committees, through 12 subcommittees mirroring federal functions, write the 12 annual appropriations bills that provide actual budget authority.
In practice the two steps blur. Many programs operate for years on appropriations alone after their formal authorization has expired, a practice called an unauthorized appropriation, and Congress routinely funds them anyway. When the 12 regular appropriations bills are not finished by the October 1 fiscal year start, Congress passes a continuing resolution extending prior-year funding levels, or funding lapses entirely.
Example: that lapse happened for 43 days from October 1 to November 12, 2025, the longest full shutdown in U.S. history2. It ended when Congress passed the Continuing Appropriations, Agriculture, Legislative Branch, Military Construction and Veterans Affairs, and Extensions Act, 2026 (P.L. 119-37), funding most agencies through January 30, 2026, at FY2025 levels.
Who holds the power
Authorizing committees decide whether a program exists and its policy rules. The Appropriations Committees, and ultimately the full House and Senate through the annual spending bills, decide whether and how much it actually gets funded. The president can veto appropriations bills, and in a shutdown, agencies must follow Antideficiency Act rules on what work can continue without funding.
Some spending is mandatory, set by permanent law such as Social Security and Medicare, and does not go through the annual appropriations process at all. That distinguishes it from discretionary spending, which does.
Where you come in
See the guides on how to contact your member of Congress about an appropriations bill and how to reach committee staff on the Appropriations Committees.
Related
Glossary: continuing resolution, discretionary spending, antideficiency-act
See also the explainer on how a bill really becomes law.