What is a government shutdown? Why it happens in the US

A government shutdown happens when the US Congress hasn't passed the laws that fund federal agencies by the deadline, so the money legally runs out. A law called the Antideficiency Act then forbids agencies to spend or promise money they don't have, and they must stop all work that isn't protected by law or needed to protect life and property. Essential staff keep working without pay, others are sent home, and both are paid once funding returns.

In short

• Shutdowns happen because federal agencies need yearly funding laws, and Congress and the president must agree on them by 1 October.
• When funding lapses, the Antideficiency Act stops all spending that isn't excepted, so agencies close what isn't essential.
• Programs funded by permanent law, such as Social Security payments, keep going; many others pause.

Why does a shutdown happen?

The federal government runs on a fiscal year that starts on 1 October. Much of what agencies spend, called discretionary spending, has to be approved every year through appropriations bills, traditionally 12 of them, each covering a group of agencies. Like any law, they must pass both the House and the Senate, where most bills need 60 votes to get past a filibuster, and be signed by the president, as in any other bill.

Congress rarely finishes all 12 on time. To buy time, it usually passes a continuing resolution, a stopgap law that keeps agencies running at roughly the previous year's levels for a few weeks or months. A shutdown starts the moment both regular funding and any stopgap run out for some agencies. That can cover the whole government, or only the agencies whose bills haven't passed, which is called a partial shutdown.

Shutdowns usually happen because funding becomes leverage. One side refuses to pass funding unless it wins something, a policy change, a spending level or a promise, and the other side refuses to give it. Neither is required to blink, and the deadline passes.

What does the Antideficiency Act require?

The Antideficiency Act, first passed in 1870 and strengthened since, bars federal officials from spending or committing money beyond what Congress has made available, or before Congress has appropriated it, as the Government Accountability Office summarizes. It also bans accepting voluntary work for the government, under 31 U.S.C. § 1342, except in emergencies involving the safety of human life or the protection of property. Officials who knowingly break it can be suspended, fired, fined or imprisoned.

For most of its history, agencies treated a short lapse in funding as a technicality and carried on. That changed in 1980 and 1981, when Attorney General Benjamin Civiletti issued legal opinions saying that the act meant what it said: without appropriations, agencies must stop work except where the law allows it. The first shutdown under that reading closed the Federal Trade Commission for a day in 1980. Every shutdown since has followed the same rules.

What closes and what keeps running?

Each agency keeps a shutdown plan that sorts its work and staff into categories. Employees whose work is "excepted", such as protecting life and property, keep working but aren't paid until the lapse ends. Others are furloughed: sent home and barred from working, even as volunteers. The Office of Personnel Management publishes the rules agencies follow.

Usually keeps running	Usually stops or slows
Military operations, with troops working, though their pay depends on funding	Many national parks, museums and federal visitor sites
Air traffic control and airport security, with staff working unpaid	New federal loans, permits and many inspections
Federal law enforcement, prisons and border protection	Much federal research and new grants
Social Security and Medicare payments, which rest on permanent law	Routine work at many agencies, from statistics to customer service
Mail delivery, since the Postal Service funds itself	Federal courts, once their reserve funds run out
Agencies funded by fees, which can keep going while the fees last	Programs that need new money each year, which can run dry as a lapse drags on

The pain grows with time. In a short lapse, many agencies coast on leftover funds. In a long one, payments that depend on yearly money can't be made: during the lapse in November 2025, the SNAP food assistance program, which needs yearly funding to pay benefits, became the subject of court cases over whether payments could continue. Workers miss paychecks, and federal contractors, who have no right to back pay, may never recover the lost income.

Federal employees are protected by a 2019 law, passed during the 35-day shutdown, which says furloughed and excepted workers are paid once funding returns. The law that ended the 2025 shutdown also reversed layoff notices agencies had issued during the lapse and provided back pay.

How often has the government shut down?

Funding gaps have happened about two dozen times since the modern budget process began in 1976, but most were brief and many fell over weekends. The ones that closed agencies for days are listed here.

Dates	Length	Notes
14–19 November 1995	5 days	Budget fight between President Bill Clinton and the Republican Congress
16 December 1995 – 6 January 1996	21 days	The same dispute; the longest at the time
1–17 October 2013	16 days	Dispute over funding the Affordable Care Act
20–22 January 2018	3 days	Dispute over immigration policy
22 December 2018 – 25 January 2019	35 days	Partial shutdown over funding for a border wall
1 October – 12 November 2025	43 days	Full lapse, the longest full shutdown in US history
31 January – 3 February 2026	A few days	Partial; ended when a law funding the Pentagon and several other departments, and extending Homeland Security funding, was signed
14 February – 30 April 2026	About 11 weeks	Limited to the Department of Homeland Security, in a dispute over immigration enforcement funding

The 2025 and 2026 dates come from the Committee for a Responsible Federal Budget's tracker. The 2025 shutdown ended when the president signed a law on 12 November that funded three groups of agencies for the full year and the rest until 30 January 2026.

Do shutdowns save money?

No. Furloughed employees are paid afterward for work they weren't allowed to do, and agencies spend money shutting down and restarting. Fees go uncollected and tax enforcement slows. Economists generally find that the economy loses some output while a shutdown lasts and gets most, but not all, of it back once the government reopens.

Still argued

Shutdowns are rare among democracies. In most parliamentary systems, a government that can't pass its budget falls, and many countries have laws that continue spending automatically if a budget is late. Proposals to do the same in the United States, through an automatic continuing resolution, have come from members of both parties. Supporters argue that shutdowns hurt workers and the public without changing outcomes. Opponents argue that automatic funding would weaken Congress's power of the purse, the main way it checks the executive branch, and remove pressure to pass real budgets. Which party bears the blame for any given shutdown is a political argument in itself, and this note takes no side in it.

A shutdown is about yearly spending, not borrowing. It is a different fight from the debt limit, which caps how much the Treasury can borrow to pay for spending Congress has already approved, and both are part of the bigger story of the national debt. Shutdowns are also one of the clearest ways the separation of powers shows up in daily life: Congress holds the purse, the president holds the pen, and when they can't agree, the money stops.

Check yourself

• Without looking back: what exactly runs out in a shutdown, and which law forces agencies to stop work?
• Why do Social Security checks keep arriving during a shutdown while many national parks close?
• What is the difference between a shutdown and hitting the debt limit?

Sources

• Appropriations law resources: the Antideficiency Act — U.S. Government Accountability Office
• 31 U.S. Code § 1342, Limitation on voluntary services — Legal Information Institute, Cornell Law School
• Furlough guidance — U.S. Office of Personnel Management, 2026
• Appropriations watch: FY 2026 — Committee for a Responsible Federal Budget, 2026