The Senate Appropriations Committee is the largest committee in the U.S. Senate, consisting of 30 members in the 117th Congress. Its role is defined by the U.S. Constitution, which requires "appropriations made by law" prior to the expenditure of any money from the Federal treasury.
The Committee, chaired by Senator Patrick Leahy (D-Vt.), writes the legislation that allocates federal funds to the numerous government agencies, departments, and organizations on an annual basis.
Twelve subcommittees are tasked with drafting legislation to allocate funds to government agencies within their jurisdictions. These subcommittees are responsible for reviewing the President's budget request, hearing testimony from government officials and other witnesses, and drafting the spending plans for the coming fiscal year. Their work is passed on to the full Senate Appropriations Committee, which may review and modify the bills and approve them for consideration by the full Senate.
The Committee is also responsible for supplemental spending bills, which are sometimes needed in the middle of a fiscal year to compensate for emergency expenses.
The Senate Appropriations Committee is located in S-128 of the Capitol, with subcommittee offices located in the Dirksen Senate Office Building.