Key takeaways
- A shutdown starts when appropriations (or a short-term continuing resolution) lapse.
- It is not a full stop: work defined as excepted or mandatory continues.
- Many employees are furloughed; others work without being paid until Congress funds the government again.
- Reopening requires Congress to pass, and the president to sign, new funding legislation.
When headlines say the U.S. government has “shut down,” it is easy to picture dark buildings and empty desks. The legal event is narrower. A shutdown is what happens when Congress has not passed spending bills — or a stopgap continuing resolution — for some or all of the federal government, and the previous funding law has expired.
The Constitution gives Congress the power of the purse. Agencies cannot spend money that Congress has not appropriated. The Antideficiency Act generally forbids federal officers from spending or obligating funds in advance of appropriations. That is the statute lawyers point to when they explain why agencies must stop many activities when funding lapses.
What actually stops
Agencies sort work into categories. Activities that are not legally allowed to continue without appropriations pause. That often includes research that is not safety-critical, routine permitting, many public-facing offices, and some national-park visitor services. The details differ by department because their statutes and contingency plans differ.
Work that protects life or property, or that is already funded by a different stream, can continue. Air traffic control, many law-enforcement functions, inpatient medical care in federal facilities, and Social Security benefit payments (which are not funded the same way as annual discretionary appropriations) are the usual examples journalists use. “Essential” is a common word in conversation; the technical term in shutdown planning is often “excepted.”
Who gets paid, and when
Members of Congress keep getting paid because their salaries sit in permanent law, not in the annual bills that expired. Many federal employees do not. Furloughed staff are sent home and, historically, have received back pay after Congress funds the government — a practice Congress later put into statute for many employees. Excepted employees may be required to work during the lapse and wait for that same catch-up paycheck.
Contractors are in a different position. They are not federal employees. Whether they are paid depends on the contract and whether the agency can legally continue the work. Many cannot bill during a lapse.
What it takes to reopen
Reopening is not an agency choice. Congress must pass legislation — often a continuing resolution that extends prior funding levels for a few weeks, or the remaining regular appropriations bills — and the president must sign it. Until that happens, agency contingency plans stay in force.
Partial shutdowns happen when some bills are enacted and others are not. Then one department can be open while another is closed. That is why “the government” is a misleading singular.
How to read the next headline
Ask three questions. Which agencies are unfunded? Which benefits are mandatory and still flow? And is Congress negotiating a short-term CR or a longer package? Those facts tell you more than a photo of a locked door.
This is a process explainer, not a prediction about any specific Congress. For current status, use official House, Senate, and agency shutdown pages.