2 U.S.C. § 642 — Budget-related legislation must be within appropriate levels

(a) Enforcement of budget aggregates. (1) In House of Representatives. Except as subsection (c) provides, after Congress completes action on a concurrent budget resolution for a fiscal year, the House may not consider a bill, joint resolution, amendment, motion, or conference report that provides new budget authority or reduces revenues if: (A) enacting the bill or resolution as reported; (B) adopting and enacting the amendment; or (C) enacting the bill or resolution in the form recommended by the conference report would exceed the total new budget authority or total outlays for the first fiscal year in the applicable budget resolution, or would make revenues lower than the resolution's total-revenue level for that first year, or for that year plus the later years for which section 633(a) provides allocations. This restriction does not apply while a congressional declaration of war is in effect. (2) In Senate. After agreement to a concurrent budget resolution, the Senate may not consider a bill, joint resolution, amendment, motion, or conference report that would exceed the resolution's total new budget authority or total outlays for the first fiscal year, or make revenues lower than the resolution's total revenues for that year or for that year plus the later years for which section 633(a) provides allocations. (3) Enforcement of Social Security levels in Senate. After agreement to a concurrent budget resolution, the Senate may not consider a bill, joint resolution, amendment, motion, or conference report that would reduce Social Security surpluses or increase Social Security deficits compared with the levels in the applicable resolution for the first fiscal year, or for that year plus the later years for which section 633(a) provides allocations.

(b) Social security levels. (1) In general. For subsection (a)(3), a Social Security surplus is the excess of Social Security revenues over Social Security outlays in a fiscal year or years with an excess. A Social Security deficit is the excess of Social Security outlays over Social Security revenues in a fiscal year or years with an excess. (2) Tax treatment. For subsection (a)(3), a provision changing chapter 1 of the Internal Revenue Code of 1986 is not treated as changing Social Security revenues or outlays unless it changes how Social Security benefits are taxed.

(c) Exception in House of Representatives. Subsection (a)(1) does not apply in the House to a bill, joint resolution, or amendment providing new budget authority for a fiscal year, or to a conference report on one, if enacting the bill or resolution as reported, adopting and enacting the amendment, or enacting the bill or resolution in the conference-report form would not exceed the appropriate allocation of new budget authority made under section 633(a) for that fiscal year.