The Constitution declares that “No Money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law.” (Article I, Section 9, Clause 7.) As James Madison explained in Federalist 58, our Constitution is based on the princple that strict controls on spending are necessary to prevent abuses of power. Hence, federal money can only be spent after Congress enacts a bill ordering the spending, and after the President signs the appropriation bill, or Congress votes to override a veto.
Several federal statutes, collectively known as “The Antideficiency Act,” provide additional safeguards. 31 U.S.C. secs. 1341-42 & 1511-17. The original version of the Act dates back to 1820. Act of May 1, 1820, ch. 52, §6, 3 Stat. 567, 568. The current Act makes it a crime for a federal employee to pay out money without prior Congressional authorization.
In 1990, Congress amended the Antideficiency Act:
An officer or employee of the United States Government or of the District of Columbia government 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. This section does not apply to a corporation getting amounts to make loans (except paid in capital amounts) without legal liability of the United States Government. As used in this section, the term “emergencies involving the safety of human life or the protection of property” 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.
31 U.S.C. 1432. See also 31 U.S.C. 1515(b) (“an emergency involving the safety of human life, the protection of property, or the immediate welfare of individuals.”). The exception does not mean that the federal government may pay for the services, but it does mean that the federal government may incur an obligation to pay for these services later. Attorney General Opinion, August 16, 1995 (Asst. A.G. Walter Dellinger).
According to a continuing legal education document by Kenneth Allen, (FAFL GLASS-CLE 6-1, Federal Publications LLC, available on Westlaw), the following activities may continue even in the absence of an appropriation. First two items which are not part of the 1342 exception: “National security activities,” and contracts payments from available funds. And under section 1342: “Medical care of inpatients and emergency outpatient care,” “Activities essential to ensuring continued public health and safety, including safe use of food, drugs, and hazardous materials,” “Border and coastal protection and surveillance,” “Protection of federal lands, buildings, waterways, equipment, and other government property,” “Care of prisoners and other persons in the custody of the United States,” “Law enforcement and criminal investigations,” “Emergency and disaster assistance,” “Activities essential to the preservation of the essential elements of the money and banking system of the United States, including borrowing and tax collection activities of the Treasury,” “Activities that ensure production of power and maintenance of the power distribution system,” and “Activities necessary to maintain government-owned research property.”
I am not an expert on the Antideficiency Act, but I hope that the above provides a starting point in considering what federal activities might continue in the absence of a continuing resolution. Commenters with expertise are welcome to supply clarifications and corrections.