How a bill becomes law

Introduction

Any member of Congress can introduce a bill. House bills are dropped into the hopper (a box on the House floor); Senate bills are handed to a clerk. The bill is assigned a number — H.R. 1234 in the House or S. 1234 in the Senate — and referred to the relevant committee.

Committee review

The committee chair decides whether to schedule hearings. If the committee approves ("reports") the bill, it moves to the full chamber's calendar. Most bills die in committee and never reach a floor vote.

Floor debate and amendments

In the House, the Rules Committee sets terms for debate (time limits, which amendments are allowed). In the Senate, debate is generally unlimited unless ended by a cloture vote. Members can propose amendments to change the bill's text.

Floor vote

The full chamber votes. A simple majority (218 of 435 in the House; 51 of 100 in the Senate) is required for most legislation. The Senate also requires 60 votes to end a filibuster via cloture before a final vote can be held.

The other chamber

The bill must pass both chambers in identical form. If the Senate changes a House bill, it goes back to the House. If they can't agree, a conference committee of members from both chambers negotiates a single version for both to vote on again.

Presidential action

The President has four options: sign it into law, veto it (returning it to Congress), take no action while Congress is in session (the bill becomes law after 10 days), or take no action when Congress has adjourned within 10 days (a "pocket veto" that kills the bill).

Veto override

Congress can override a veto with a two-thirds vote in both chambers. This requires 290 votes in the House and 67 in the Senate — a high bar that is rarely met.