US Code
SUBCHAPTER II— EMPLOYEES, EXPENSES, AND ALLOWANCES
§ 6316. United States Code Annotated or United States Code Service; procurement for Senators

(1) one copy of each of the volumes of the United States Code Annotated being published at the time the Senator takes office, and, as long as that Senator holds office, one copy of each replacement volume, each annual pocket part, and each pamphlet supplementing each such pocket part to the United States Code Annotated; or
(2) one copy of each of the volumes of the United States Code Service being published at the time the Senator takes office, and, as long as that Senator holds office, one copy of each replacement volume and each pocket supplement to the United States Code Service.