A spending bill is a type of legislation in the United States that appropriates federal funds to specific federal government departments, agencies, and programs). The money provided by the bill is used to fund operations, personnel, equipment, and activities). Appropriations bills are one part of a larger United States budget and spending process, which includes the presidents budget proposal, congressional budget resolutions, and the 302(b) allocation). The U.S. Constitution gives Congress the power to make appropriations, stating that "No money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law...").

There are twelve different ordinary appropriations bills that need to be passed each year to fund the federal government and avoid a government shutdown. These bills are typically written, debated, and passed by the House and the Senate during the summer. However, these versions can be different, especially if different parties control each chamber. The omnibus negotiating process takes place later in the year, and involves reconciling differences in the various bills so that an identical, combined appropriations bill can pass both chambers and avert a government shutdown. An omnibus spending bill is a type of bill that packages many of the smaller ordinary appropriations bills into one larger single bill that can be passed with only one vote in each house of Congress.

The Consolidated Appropriations Act, 2023 is an example of a spending bill that provides funding for various federal government departments and programs. The bill includes discretionary funding, as well as mandatory funding for programs such as the Supplemental Nutrition Assistance Program (SNAP) and child nutrition programs. The bill also provides funding for the Department of Defense. The House appropriation is contained in one of 12 acts named the Legislative Branch Appropriations Bill. Congress passes 12 annual appropriation acts, as well as supplemental appropriation acts, each year. These appropriation acts provide budget authority to obligate and expend funds from the U.S. Treasury for specific purposes.