A government shutdown starts with a funding gap. The Congressional Research Service defines one this way: "If there is an interval during a fiscal year when appropriations for a particular project or activity are not enacted into law, either in the form of a regular appropriations act or a CR, a funding gap (also referred to as a funding lapse) may occur." What follows is the shutdown itself: "When a funding gap occurs, federal agencies are generally required to begin a shutdown of the affected projects and activities, which includes the prompt furlough of non-excepted personnel."

The two are not the same event, and CRS says so directly: "Although a shutdown may be the result of a funding gap, the two events should be distinguished." A gap can pass without much shutting down at all — the Office of Management and Budget "has previously indicated that a shutdown of agency operations within the first day of the funding gap may be postponed if a resolution appears to be imminent," and CRS records that "Many of the funding gaps that have occurred since FY1977 do not appear to have resulted in 'shutdowns.'" A single year can also produce several: "Multiple funding gaps may occur within a fiscal year."

What the Antideficiency Act Requires

The rule that forces agencies to stop is 31 U.S.C. 1341, part of what is commonly called the Antideficiency Act. It provides that "Except as specified in this subchapter or any other provision of law, an officer or employee of the United States Government or of the District of Columbia government may not" — among other things — "make or authorize an expenditure or obligation exceeding an amount available in an appropriation or fund for the expenditure or obligation," or "involve either government in a contract or obligation for the payment of money before an appropriation is made unless authorized by law."

The companion section closes the obvious workaround. Under 31 U.S.C. 1342, an officer or employee "may not accept voluntary services for either government or employ personal services exceeding that authorized by law except for emergencies involving the safety of human life or the protection of property." The same section then narrows that exception: the phrase "does not include ongoing, regular functions of government the suspension of which would not imminently threaten the safety of human life or the protection of property."

The timing comes from the calendar. "The federal fiscal year runs from October 1 to September 30," and, as CRS puts it, "Congress has not typically completed its consideration of regular appropriations bills before the start of the next fiscal year on October 1."

Excepted, Exempt, Essential

Three words get used loosely and mean different things. The statute uses excepted: 31 U.S.C. 1341(c)(1)(D) provides that "the term 'excepted employee' means an excepted employee or an employee performing emergency work, as such terms are defined by the Office of Personnel Management or the appropriate District of Columbia public employer, as applicable." CRS describes the executive-branch usage more fully: "In the executive branch, and in the context of a funding gap, the term 'excepted' may refer to (1) the government activities that must continue during a funding gap and (2) the federal employees who are not furloughed and who must continue to come to work during a funding gap."

Essential is the colloquial one. "News media sometimes use the term 'essential' instead of 'excepted,'" CRS notes, and the executive branch itself once did: "In the executive branch, this term was used similarly in the early 1980s." Then it stopped. "Since then, the term gradually has disappeared from official use in the executive branch in favor of 'excepted,' in part to prevent a colloquial interpretation of the term 'essential' as referring to relative importance or value." The objection is on the record: "In congressional hearings that focused on the first FY1996 shutdown, some witnesses regretted that the terms 'nonessential' and 'essential' had been used to describe employees subject to furlough, and not subject to furlough, respectively. Use of the term 'nonessential' was a misnomer and demeaning, they said."

One caveat on how far the executive-branch vocabulary reaches: "The legislative and judicial branches are not guided officially by executive branch documents regarding the Antideficiency Act's exceptions and related terms. However, they continue to be guided by the Constitution and the act itself, and may look to executive branch guidelines as a point of reference."

OMB Circular A-11, section 124 sets out the categories. "An agency may still incur an obligation in the absence of an appropriation for certain 'excepted' functions," it says, including when:

  • "A statute or court order expressly authorizes or requires an agency to obligate funds in advance of appropriations for the subject function";
  • "The lawful continuation of funded or unfunded functions necessarily implies that the subject function must also continue because suspension of that subject function would prevent or significantly damage the execution of the other lawfully continuing functions";
  • "The subject function addresses emergency circumstances such that the suspension of the function would imminently threaten the safety of human life or the protection of property"; or
  • the "subject function is necessary to discharge the President's Constitutional duties and powers."

Excepted is not the same as exempt — though CRS notes the usage is not clean in practice: "Some agencies have used the term 'exempt' as a synonym for 'excepted.'" Formally they differ. In OMB's words, "Agency functions that are financed with appropriations that have not lapsed may continue and are 'exempt' from any shutdown procedures, even while a lapse has occurred in other appropriations." On the personnel side, CRS records that "for purposes of general usage across the executive branch, OPM defines 'exempt' as referring to employees who are not subject to furlough, because the employees' compensation is not funded by annually appropriated funds."

Who Decides What Stops

Not the general counsel's office on its own. Under A-11, "agency heads, in consultation with their general counsels, must decide what agency activities are excepted or otherwise legally authorized to continue during a lapse in appropriations." The same officials write the plan: "Agency heads, in consultation with their general counsels, must develop and maintain plans for an orderly shutdown in the event of a lapse in appropriations. Each agency must have an up-to-date lapse plan on file with OMB."

OMB runs the clock around those plans. Section 124.3 opens with the standing arrangement — "OMB will monitor the status of congressional actions on appropriations bills and will notify agencies if shutdown plans are to be implemented" — and then sets one fixed checkpoint inside it: "One week prior to the expiration of appropriations bills, regardless of whether the enactment of appropriations appears imminent, OMB will communicate with agency senior officials to remind agencies of their responsibilities to review and update orderly shutdown plans, and will share a draft communication template to notify employees of the status of appropriations."

Shutting down itself creates obligations, and the circular supplies authority for exactly those and no more: "You are automatically apportioned the amounts necessary to carry out your agency's shutdown plan as required by this section. This automatic apportionment provides authority to incur obligations, but does not provide any authority to liquidate such obligations." Paying is a separate thing from owing. CRS records that "the opinions of OLC and OMB do not permit outlays" — "the issuance of checks, disbursement of cash, or electronic transfer of funds" — "to liquidate federal obligations for operations that lack appropriated funding during a shutdown."

What Keeps Running

The concrete list is old. CRS records that "an OMB memorandum of November 17, 1981, from Director David A. Stockman to the heads of executive agencies, identified concrete 'examples of excepted activities'" — a memorandum that "still was in effect for the FY1996 shutdowns and posted online by OPM as a reference for agencies for the FY2014 shutdown." Its examples of activities that protect life and property include "Medical care of inpatients and emergency outpatient care"; "The continuance of air traffic control and other transportation safety functions and the protection of transport property"; "Border and coastal protection and surveillance"; "Care of prisoners and other persons in the custody of the United States"; "Law enforcement and criminal investigations"; and "Emergency and disaster assistance."

Money that has not lapsed also keeps working. CRS notes that "GAO later summarized the 1981 Civiletti opinion as identifying four sub-types of 'authorized by law' exceptions," the first being "Activities funded with appropriations of budget authority that do not expire at the end of one fiscal year, such as multiple-year and no-year appropriations." Those activities "may continue when the multiple-year and no-year appropriations still have budget authority that is available for obligation at the time of a funding gap."

Mandatory Programs: It Depends

The two categories are defined by which law controls them. "Discretionary funding refers to budget authority (i.e., authority to incur financial obligations that result in government expenditures) that is provided in and controlled by annual appropriations acts," CRS writes, while "mandatory funding refers to budget authority that is provided in and controlled by laws other than annual appropriations acts." The line is not clean: "Some budget authority provided in annual appropriations acts for certain programs is treated as mandatory, however, because the relevant authorizing legislation entitles beneficiaries to receive payment or otherwise obligates the government to make payment."

It does not follow that mandatory programs sail through untouched. CRS is explicit that such programs "may, or may not, be affected by a funding gap. Specific circumstances appear to be significant." The reason is administrative: "although the funds needed to make payments to beneficiaries may be available automatically pursuant to permanent appropriations, the payments may be processed by employees who are paid with funds provided in annual appropriations acts."

The Social Security Administration during the FY1996 shutdowns is the worked example CRS gives. SSA initially retained 4,780 employees, most of them "in direct service positions to ensure the continuance of benefits to currently enrolled Social Security, SSI and Black Lung beneficiaries." "SSA furloughed its remaining 61,415 employees." Before long, CRS records, SSA and OMB reconsidered — the retained staff could not answer calls from people who needed a card to work or a change of address for next month's check.

Getting Paid

Back pay is not something the bill ending a shutdown has to grant. It is standing law, written in two steps during the FY2019 lapse: subsection (c) was added to 31 U.S.C. 1341 by Pub. L. 116-1 on January 16, 2019, and nine days later Pub. L. 116-5 — the continuing resolution that ended that lapse — "inserted ', and subject to the enactment of appropriations Acts ending the lapse' before period at end" of paragraph (2). As it now reads, 31 U.S.C. 1341(c)(2) provides that "Each employee of the United States Government or of a District of Columbia public employer furloughed as a result of a covered lapse in appropriations shall be paid for the period of the lapse in appropriations, and each excepted employee who is required to perform work during a covered lapse in appropriations shall be paid for such work, at the employee's standard rate of pay, at the earliest date possible after the lapse in appropriations ends, regardless of scheduled pay dates, and subject to the enactment of appropriations Acts ending the lapse."

A "covered lapse in appropriations" "means any lapse in appropriations that begins on or after December 22, 2018," so every lapse since then is inside it. Before that provision existed, the outcome was custom rather than entitlement: "The general practice of the federal government after the shutdown has ended has been to retroactively pay furloughed employees for the time they missed, as well as employees who were required to come to work."

How Long Funding Gaps Last

CRS keeps the count. "Since FY1977, 23 funding gaps have occurred, ranging in duration from 1 day to 75 full days," and "About half of these funding gaps were brief (i.e., three days or less in duration)." The early ones were different in kind: "Six of the funding gaps, lasting between 8 days and 17 days, occurred between FY1977 and FY1980" — "before the Civiletti opinions were issued and for which there was no government shutdown."

Two more modern gaps sit in the middle of the table. FY1996 had two, of 5 and 21 full days, the second ending January 6, 1996 — "two gaps covering a total of 26 days in FY1996." FY2014's ran 16 full days, from the expiry of budget authority on September 30, 2013 to October 17, 2013.

The FY2019 gap "began with the expiration of P.L. 115-298 at midnight on December 21, 2018" and ended with the enactment of a continuing resolution on January 25, 2019. Counting the days for which no budget authority was available, "The funding gap lasted 34 full days."

It has since been exceeded twice. "At the beginning of FY2026, none of the 12 regular appropriations bills had been enacted, nor had a CR been enacted to provide budget authority for the projects and activities covered by those 12 bills." That gap ran from the start of the fiscal year until P.L. 119-37 was signed on November 12, 2025: "The funding gap lasted 42 full days."

Two more followed in the same fiscal year. "A second funding gap occurred beginning January 31, 2026, and lasted three full days until legislation was enacted on February 3" — the five-act package and Homeland Security stop-gap enacted as P.L. 119-75. Then "On February 14, 2026, a third funding gap began affecting the Department of Homeland Security." "This funding gap ended when P.L. 119-86 was enacted on April 30, 2026, providing funding covered by the regular appropriations act for the Department of Homeland Security, except U.S. Customs and Border Protection and U.S. Immigration and Customs Enforcement (Division A)." "The funding gap lasted 75 full days." That one was narrow as well as long: "the third funding gap in FY2026 affected only accounts funded in the Department of Homeland Security Appropriations Act."

The Appropriations Deadline and Fiscal Year

The federal fiscal year runs October 1 through September 30, and there are 12 regular appropriations bills to enact before it begins. Congress rarely finishes on time, so it "may use one or more continuing appropriations acts (often referred to as a 'continuing resolution' or a CR) to provide interim funding" while negotiations continue. The full-year acts then often arrive in packages rather than one at a time — see our guide to the omnibus and the minibus. FY2026 is the illustration: "P.L. 119-37 included continuing appropriations through January 30, 2026, covering nine regular appropriations bills (Division A), as well as regular appropriations for all of FY2026 for Agriculture (Division B), Legislative Branch (Division C), and Military-Construction-VA (Division D)," and P.L. 119-75 followed by "incorporating five regular appropriations acts for FY2026 and a CR covering the Department of Homeland Security Appropriations Act through February 13, 2026."

The deadline is not only October 1. As CRS puts it, "Although funding gaps may occur at the start of the fiscal year, they may also occur any time a CR expires and another CR (or the regular appropriations bill) is not enacted immediately thereafter." FY2026 alone produced "three gaps covering a total of 120 days." LegislationPatch tracks appropriations legislation as it moves; a CR or funding bill in progress appears in our database with its current legislative stage.

Key Sources

Drafted from primary source documents by LegislationPatch's automated research pipeline, then reviewed, verified, and edited by , Editor. Every figure and citation is checked against the official text before publication. See our editorial standards and AI disclosure.