Antideficiency Act

The Antideficiency Act (ADA) (Pub. L.97–258, 96 Stat.923) is legislation enacted by the United States Congress to prevent the incurring of obligations or the making of expenditures (outlays) in excess of amounts available in appropriations or funds. The law was initially enacted in 1884, with major amendments occurring in 1950 (64 Stat.765) and 1982 (96 Stat.923). It is now codified at 31 U.S.C.§ 1341, § 1342, §§ 1349–1351 and §§ 1511–1519. The Act was previously enacted as section 3679 of the Revised Statutes.

The ADA prohibits the U.S. federal government from entering into a contract that is not "fully funded" because doing so would obligate the government in the absence of an appropriation adequate to the needs of the contract. Accordingly, it is often cited during U.S. government shutdowns as a reason for the closure of certain departments or facilities.