Amendments & Substitutes

Legislation is rarely static. Members of Congress regularly propose amendments — formal changes to the text — to refine, redirect, or sometimes entirely replace a bill. These changes can happen in committee or on the chamber floor, and they’re an essential part of how Congress negotiates policy.

1. What an Amendment Is

An amendment is a proposed change to the wording of a bill or resolution. It can add new sections, delete provisions, or modify existing language.

Amendments are formally offered by a member and must be agreed to by the chamber.
They can be adopted (agreed to), rejected, or withdrawn.

Every amendment is tracked by Congress.gov with its own identifier and sponsor.

2. Types of Amendments

Most amendments fall into two main categories:

First-degree amendments: Directly change the bill text.
Second-degree amendments: Modify a first-degree amendment before it’s voted on.

Only one amendment and one amendment to that amendment can be pending at a time under standard House and Senate rules.

3. Committee Amendments (Markups)

Most amendments originate in committees during “markup” sessions — detailed reviews of a bill line by line.

Members propose edits or replacements section by section.
Adopted changes are incorporated into the version “reported” to the full chamber.

Committee markups are where much of the real lawmaking occurs, often shaping the bill’s core language.

4. Floor Amendments

Once a bill reaches the floor, any member (within procedural limits) may offer amendments. These must be approved by a simple majority to be added.

In the House, amendments must usually be germane — related to the subject of the bill.
In the Senate, rules are looser; nongermane amendments are sometimes allowed.

This flexibility is why Senate amendments can occasionally transform a bill’s purpose.

5. Amendment in the Nature of a Substitute

A substitute amendment replaces the entire text of a bill with new language. It’s often used to merge competing drafts or implement leadership-negotiated compromises.

Technically still an amendment, but functionally a rewrite.
Can serve as a vehicle for an entirely different policy package.

Many major laws began as substitutes to unrelated bills — a common procedural shortcut.