House Offset Amendments to Appropriations Bills: Procedural Considerations [November 30, 2016] [open pdf - 670KB]
"One of the most common methods for changing spending priorities in appropriations bills on the House floor is through 'offset amendments'. House offset amendments may generally change spending priorities in a pending appropriations measure by increasing spending for certain activities (or creating spending for new activities not previously included in the bill) and offsetting the increase with funding decreases in other activities in the bill. Offset amendments are needed to avoid points of order under Sections 302(f) and 311(a) of the Congressional Budget Act, enforcing certain spending ceilings affecting regular appropriations bills, continuing resolutions (CRs), and supplemental appropriations measures (supplementals). In addition, amendments to general appropriations bills that would increase total spending provided in the bill must be entirely offset. Two types of House offset amendments are considered in the Committee of the Whole House on the State of the Union (Committee of the Whole): clause 2(f) and reachback (or fetchback) amendments. As provided under House Rule XXI, clause 2(f) offset amendments consist of two or more amendments considered together (or en bloc) that would change amounts by directly adding text or changing text in the body of the bill. Taken as a whole, the amendment does not increase the amount of funding in the pending bill. Such amendments (1) must provide offsets in both new budget authority and outlays, (2) can only include language transferring appropriations in the bill, and (3) may contain certain unauthorized appropriations."
CRS Report for Congress, RL31055
via Federation of American Scientists: http://www.fas.org/sgp/crs/index.html