The routine activities of most federal agencies are funded annually by one or more of the regular appropriations acts. When action on the regular appropriations acts is delayed, a continuing appropriations act, also sometimes referred to as a continuing resolution or CR, may be used to provide interim budget authority. Since the federal fiscal year was shifted to October 1-September 30 beginning with FY1977, all of the regular appropriations acts have been enacted by the beginning of the fiscal year in only four instances (FY1977, FY1989, FY1995, and FY1997), although CRs were not needed for interim funding in one of these fiscal years. CRs were enacted for FY1977 but only to fund certain unauthorized programs whose funding had been excluded from the regular appropriations acts. The Antideficiency Act (31 U.S.C. 1341-1342, 1511-1519) generally bars the obligation or expenditure of federal funds in the absence of appropriations. The 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, is referred to as a funding gap or funding lapse . 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 relevant regular appropriations bill) is not enacted immediately thereafter. Multiple funding gaps may occur within a fiscal year. In 1980 and early 1981, then-Attorney General Benjamin Civiletti issued opinions in two letters to the President that have been put into effect through guidance provided to federal agencies under various Office of Management and Budget (OMB) circulars clarifying the limits of federal government activities upon the occurrence of a funding gap. The Civiletti letters state that, in general, the Antideficiency Act requires that if Congress has enacted no appropriation beyond a specified period, the agency may make no contracts and obligate no further funds except as "authorized by law." In addition, because no statute generally permits federal agencies to incur obligations without appropriations for the pay of employees, the Antideficiency Act does not, in general, authorize agencies to employ the services of their employees upon a lapse in appropriations, but it does permit agencies to fulfill certain legal obligations connected with the orderly termination of agency operations. The second letter, from January 1981, discusses the more complex problem of interpretation presented with respect to obligational authorities that are "authorized by law" but not manifested in appropriations acts. In a few cases, Congress has expressly authorized agencies to incur obligations without regard to available appropriations. More often, it is necessary to inquire under what circumstances statutes that vest particular functions in government agencies imply authority to create obligations for the accomplishment of those functions despite a lack of current appropriations. It is under this guidance that exceptions may be made for activities involving "the safety of human life or the protection of property." As a consequence of these guidelines, when a funding gap occurs, executive agencies begin a shutdown of the affected projects and activities, including the furlough of non-excepted personnel. 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. Under current practice, although a shutdown may be the result of a funding gap, the two events should be distinguished. This is because a funding gap may result in a shutdown of all affected projects or activities in some instances but not in others. For example, when a funding gap is of a short duration, agencies may not have enough time to complete a shutdown of affected projects and activities before funding is restored. In addition, the Office of Management and Budget has previously indicated that a shutdown of agency operations within the first day of a funding gap may be postponed if it appears that an additional CR or regular appropriations act is likely to be enacted that same day. To avoid funding gaps, proposals have previously been offered to establish an "automatic continuing resolution" (ACR) that would provide a fallback source of funding authority for activities, at a specified formula or level, in the event that timely enactment of appropriations is disrupted. Funding would become available automatically and remain available as long as needed so that a funding gap would not occur. Although the House and Senate have considered ACR proposals in the past, none has been enacted into law on a permanent basis. As illustrated in Table 1 , there have been 20 funding gaps since FY1977. The enactment of a CR on the day after the budget authority in the previous CR expired, which has occurred in several instances, is not counted in this report as involving a funding gap because there was no full day for which there was no available budget authority. For example, between FY2000 and FY2018, "next-day" CRs were enacted on 21 occasions. A majority of the funding gaps occurred between FY1977 and FY1995. During this period of 19 fiscal years, 15 funding gaps occurred. Multiple funding gaps have occurred during a single fiscal year in four instances: (1) three gaps covering a total of 28 days in FY1978, (2) two gaps covering a total of four days in FY1983, (3) two gaps covering a total of three days in FY1985, and (4) two gaps covering a total of 26 days in FY1996. Seven of the funding gaps commenced with the beginning of the fiscal year on October 1. The remaining 13 funding gaps occurred at least more than one day after the fiscal year had begun. Ten of the funding gaps ended in October, four ended in November, three ended in December, and three ended in January. Funding gaps have ranged in duration from 1 to 34 full days. Six of the 8 lengthiest 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. Between 1980 and 1990, the duration of funding gaps was generally shorter, typically ranging from one day to three days. In most cases these occurred over a weekend with only limited impact in the form of government shutdown activities. Notably, many of the funding gaps that have occurred since FY1977 do not appear to have resulted in a "shutdown." Prior to the issuance of the Civiletti opinions, the expectation was that agencies would not shut down during a funding gap. Continuing resolutions typically included language ratifying obligations incurred prior to the resolution's enactment. For example, the first CR for FY1980 provided All obligations incurred in anticipation of the appropriations and authority provided in this joint resolution are hereby ratified and confirmed if otherwise in accordance with the provisions of the joint resolution. Thus, while agencies tended to curtail some operations in response to a funding gap, they often "continued to operate during periods of expired funding." In addition, some of the funding gaps after the Civiletti opinions did not result in a completion of shutdown operations due to both a funding gap's short duration and an expectation that appropriations would soon be enacted. For example, during the three-day FY1984 funding gap, "no disruption to government services" reportedly occurred, due to both the three-day holiday weekend and the expectation that the President would soon sign into law appropriations passed by the House and Senate during that weekend. Some of the funding gaps during this period, however, did have a broader impact on affected government operations, even if only for a matter of hours. For example, in response to the one-day funding gap that occurred on October 4, 1984, a furlough of non-excepted personnel for part of that day was reportedly implemented. It should be noted that when most of these funding gaps occurred, one or more regular appropriations measures had been enacted, so any effects were not felt government-wide. For example, the three funding gaps in FY1978 were limited to activities funded in the Departments of Labor and Health, Education, and Welfare Appropriations Act. Similarly, 8 of 13 regular appropriations acts had been enacted prior to the three-day funding gap in FY1984. The most recent funding gaps—two in FY1996, one in FY2014, one in FY2018, and one in FY2019—all resulted in widespread cessation of non-excepted activities and furlough of associated personnel. The legislative history of these funding gaps are summarized below. The two FY1996 funding gaps occurred between November 13 and 19, 1995, and December 15, 1995, through January 6, 1996. The chronology of regular and continuing appropriations enacted during that fiscal year is illustrated in Figure 1 . In the lead-up to the first funding gap, only 3 out of the 13 regular appropriations acts had been signed into law, and budget authority, which had been provided by a CR since the start of the fiscal year, expired at the end of the day on November 13. On this same day, President Clinton vetoed a CR that would have extended budget authority through December 1, 1995, because of the Medicare premium increases contained within the measure. The ensuing funding gap reportedly resulted in the furlough of an estimated 800,000 federal workers. After five days, a deal was reached to end the shutdown and extend funding through December 15. Agencies that had been zeroed out in pending appropriations bills were funded at a rate of 75% of FY1995 budget authority. All other agencies were funded at the lower of the House- or Senate-passed level of funding contained in the FY1996 full-year appropriations bills. The CR also included an agreement between President Clinton and Congress regarding future negotiations to lower the budget deficit within seven years. During the first FY1996 funding gap and prior to the second one, an additional four regular appropriations measures were enacted, and three others were vetoed. The negotiations on the six remaining bills were unsuccessful before the budget authority provided in the CR expired at the end of the day on December 15, 1995. Reportedly, about 280,000 executive branch employees were furloughed during the funding gap between December 15, 1995, and January 6, 1996. A CR to provide benefits for veterans and welfare recipients and to keep the District of Columbia government operating was passed and signed into law on December 22, 1995. The shutdown officially ended on January 6, 1996, when the first of a series of CRs to reopen affected agencies and provide budget authority through January 26, 1996, was enacted. This funding gap commenced at the beginning of FY2014 on October 1, 2013. None of the 12 regular appropriations bills for FY2014 was enacted prior to the beginning of the funding gap. Nor had a CR to provide budget authority for the projects and activities covered by those 12 bills been enacted. On September 30, however, an ACR was enacted to cover FY2014 pay and allowances for (1) certain members of the Armed Forces, (2) certain Department of Defense (DOD) civilian personnel, and (3) other specified DOD and Department of Homeland Security contractors ( H.R. 3210 ; P.L. 113-39 , 113 th Congress). At the beginning of this 16-day funding gap, more than 800,000 executive branch employees were reportedly furloughed. This number was reduced during the course of the funding gap due to the implementation of P.L. 113-39 and other redeterminations of whether certain employees were excepted from furlough. Prior to the resolution of the funding gap, congressional action on appropriations was generally limited to a number of narrow CRs to provide funding for certain programs or classes of individuals. Of these, only the Department of Defense Survivor Benefits Continuing Appropriations Resolution of 2014 ( H.J.Res. 91 ; P.L. 113-44 ) was enacted into law. On October 16, 2013, the Senate passed H.R. 2775 , which had been previously passed by the House on September 12, with an amendment. This amendment, in part, provided interim continuing appropriations for the previous year's programs and activities through January 15, 2014. Later that same day, the House agreed to the Senate amendment to H.R. 2775 . The CR was signed into law on October 17, 2013 ( P.L. 113-46 ), thus ending the funding gap. At the beginning of FY2018, none of the 12 regular appropriations bills had been enacted, so the federal government operated under a series of CRs. The first, P.L. 115-56 , provided government-wide funding through December 8, 2017. The second, P.L. 115-90 , extended funding through December 22, and the third, P.L. 115-96 , extended it through January 19, 2018. In the absence of agreement on legislation that would further extend the period of these CRs, however, a funding gap began with the expiration of P.L. 115-96 at midnight on January 19. A furlough of federal personnel began over the weekend and continued through Monday of the next week, ending with enactment of a fourth CR, P.L. 115-120 , on January 22. At the beginning of FY2019, 5 of the 12 regular appropriations bills had been enacted in two consolidated appropriations bills. The remaining seven regular appropriations bills were funded under two CRs. The first CR, P.L. 115-245 , provided funding through December 7, 2018. The second CR, P.L. 115-298 , extended funding through December 21, 2018. When no agreement was reached on legislation to further extend the period of these CRs, a funding gap began with the expiration of P.L. 115-298 at midnight on December 21, 2018. Because of this funding gap, federal agencies and activities funded in these seven regular appropriations bills were required to shut down. The funding gap ended when a CR, P.L. 116-5 , was signed into law on January 25, 2019, which ended the partial government shutdown and allowed government departments and agencies to reopen. The funding gap lasted 34 full days.

Answer: The Antideficiency Act (31 U.S.C. 1341-1342, 1511-1519) generally bars the obligation of funds in the absence of appropriations. Exceptions are made under the act, including for activities involving "the safety of human life or the protection of property." The interval during the 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 continuing resolution (CR), is referred to as a funding gap or funding lapse. 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. Multiple funding gaps may occur within a fiscal year. 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 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. Although a shutdown may be the result of a funding gap, the two events should be distinguished. This is because a funding gap may result in a total shutdown of all affected projects or activities in some instances but not others. For example, when funding gaps are of a short duration, agencies may not have enough time to complete a shutdown of affected projects and activities before funding is restored. In addition, 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. Since FY1977, 20 funding gaps occurred, ranging in duration from 1 day to 34 full days. These funding gaps are listed in Table 1. About half of these funding gaps were brief (i.e., three days or less in duration). Notably, many of the funding gaps do not appear to have resulted in a "shutdown." Prior to the issuance of the opinions in 1980 and early 1981 by then-Attorney General Benjamin Civiletti, while agencies tended to curtail some operations in response to a funding gap, they often "continued to operate during periods of expired funding." In addition, some of the funding gaps after the Civiletti opinions did not result in a completion of shutdown operations due to both the funding gap's short duration and an expectation that appropriations would soon be enacted. Some of the funding gaps during this period, however, did have a broader impact on affected government operations, even if only for a matter of hours. Two funding gaps occurred in FY1996, amounting to 5 days and 21 days. The chronology of regular and continuing appropriations enacted during FY1996 is illustrated in Figure 1. At the beginning of FY2014 (October 1, 2013), none of the regular appropriations bills had been enacted, so a government-wide funding gap occurred. It concluded on October 17, 2013, after lasting 16 full days. During FY2018, there was a funding gap when a CR covering all of the regular appropriations bills expired on January 19, 2018. It concluded on January 22, 2018, after lasting two full days. The most recent funding gap occurred during FY2019, when a CR covering federal agencies and activities funded in 7 of the 12 regular appropriations bills expired on December 21, 2018. It concluded on January 25, 2019, after lasting 34 full days. For a general discussion of federal government shutdowns, see CRS Report RL34680, Shutdown of the Federal Government: Causes, Processes, and Effects, coordinated by Clinton T. Brass.