The Byrd Rule

Budget reconciliation bills cannot be filibustered in the Senate and need only a simple majority, which makes them attractive vehicles for major legislation. To keep reconciliation from becoming a way around the filibuster for any policy, Senator Robert Byrd of West Virginia won adoption of a rule in October 1985 barring extraneous matter, and in 1990 it was written permanently into the Congressional Budget Act as Section 313. It applies only in the Senate.

A provision is extraneous under the Byrd rule if it does not change spending or revenue, if its budget effect is merely incidental to its policy purpose, if it falls outside the jurisdiction of the committee that reported it, if it increases the deficit beyond the years covered by the budget resolution, or if it changes Social Security. Any senator can raise a point of order against an extraneous provision, and waiving the rule takes 60 votes. The presiding officer rules on the advice of the Parliamentarian, and the review of a bill before floor action is known informally as the Byrd bath.

The rule shapes the content of major laws. The ban on deficits beyond the budget window is why the individual tax cuts in the 2001 and 2017 reconciliation laws were written to expire. During work on the reconciliation law signed on July 4, 2025, the Parliamentarian advised that several provisions violated the rule and they were dropped or rewritten, and the Senate majority used a current-policy baseline to treat the extension of expiring tax cuts as costing nothing. Supporters say the Byrd rule preserves the filibuster and keeps reconciliation focused on budgets, while critics say it produces convoluted policy and gives an unelected official too much influence.