A legislative amendment is a proposed change to a bill and serves as a critical tool to refine and reshape proposals as they move through Congress; sometimes the process completely transforms a bill before it becomes law. How a bill gets amended is a fundamental part of lawmaking and requires a lot of negotiation and compromise.
How a Bill Gets Amended
Once introduced, a bill is referred to a committee (or more than one), which sometimes holds hearings before the markup session: the period when members can debate, revise, and vote on proposed amendments. Changes can be minor adjustments in wording or complete substitutes that replace entire sections of a bill. If the committee approves changes and reports the bill, the revised text goes to the full chamber where lawmakers can propose further changes while the House or Senate considers the bill.
There are some differences in the amendment process between the House and Senate. For example, in the House, the Rules Committee usually sets the terms for considering major legislation, including which floor amendments may be offered and under what conditions. In the Senate, members have more opportunities to offer amendments, and changes usually don't need to be germane (relevant) to the bill.
When one chamber passes a bill with changes, it sends the revised bill to the other chamber, where it may undergo committee review, floor debate, further changes, and a vote. If the House and Senate pass different versions, they must resolve their differences before the bill advances. One chamber may agree to the other’s changes through a concurrence vote, or the chambers may negotiate through an exchange of amendments or a conference committee.
Both chambers must ultimately pass identical legislative text. If a conference committee reaches a compromise, the House and Senate vote to approve or reject the conference report, which can’t be altered on the floor.
Once the House and Senate agree on the same final text, the bill is enrolled (prepared in its final form) and sent to the president to sign or veto.
