How Does the Amendment Process Work: Congress, States, Deadlines

Amending the U.S. Constitution takes two supermajorities: a proposal approved by two-thirds of both houses of Congress (or by a convention called when two-thirds of state legislatures ask for one), followed by ratification from three-fourths of the states. That is how the constitutional amendment process works, and it is spelled out in Article V of the Constitution itself. The design is deliberately hard to clear. Thousands of amendments have been introduced in Congress since 1789, and only twenty-seven have ever made it in.¹

Step One: Proposing an Amendment

Every amendment starts with a formal proposal. Article V provides two ways to get one.

Through Congress

The route used for every successful amendment in American history runs through Congress. Either the House or the Senate can introduce a joint resolution proposing an amendment, and the resolution has to pass both chambers by a two-thirds vote. That threshold applies to members present and voting once a quorum exists, not to the full membership of each chamber.² Even at that reading, the bar is high enough that most proposals die in committee.

Through a Convention of the States

Article V also gives states their own path. If two-thirds of state legislatures (currently thirty-four) submit applications, Congress must call a convention to propose amendments.¹ No amendment has ever been proposed this way. As of early 2026, thirty-three states have active convention applications on file, one short of the trigger.

The convention path also carries a legal question no one has resolved: whether a convention can be limited to a single topic, or whether it could propose amendments on anything the delegates chose. Some scholars read Article V as allowing states to restrict the scope of their applications; others argue it authorizes only a general convention with no enforceable topic limits.³ That uncertainty is the main reason states have never crossed the threshold.

Step Two: What Happens After Congress Passes a Proposal

Once a joint resolution clears both chambers, it goes to the National Archives, not the White House. The President has no role in the amendment process at all. The Supreme Court settled this in 1798 in Hollingsworth v. Virginia, holding that a proposed amendment needs no presidential signature and cannot be vetoed.²

At the Archives, the Office of the Federal Register processes the resolution, publishes it in slip law format, and assembles an information package with formal copies of the resolution and the ratification procedures. The Archivist of the United States then sends the package to every state governor, which officially starts the ratification process.⁴

The joint resolution itself specifies which ratification method the states will use: approval by state legislatures, or approval by state ratifying conventions convened specifically for the purpose. Congress makes that choice, and the same method applies in all fifty states.¹

Step Three: Ratification by the States

Three-fourths of the states must ratify a proposed amendment for it to become part of the Constitution. With fifty states, that number is thirty-eight. Every successful amendment except one has been ratified through state legislatures, with each state following its own internal procedures for bringing the question to a vote.²

The exception is the Twenty-First Amendment, which repealed Prohibition in 1933. Congress directed that it be ratified by state conventions rather than legislatures. Many state legislatures at the time were sympathetic to Prohibition, and convention delegates could be elected specifically on the repeal question.⁵

States cannot add their own steps to the process. In Hawke v. Smith (1920), the Supreme Court struck down an Ohio requirement that a legislative ratification be confirmed by a public referendum. Ratifying a federal amendment, the Court held, is not ordinary legislation; it is an act of assent that derives from the federal Constitution, and states cannot attach extra conditions to it.⁶

Can a State Take Back a Ratification?

Whether a state can rescind a ratification it already submitted is one of the murkiest questions in constitutional law. In Coleman v. Miller (1939), the Supreme Court called the issue a “political question” for Congress rather than the courts. During the Fourteenth Amendment fight, two states tried to rescind their ratifications, Congress declared the rescissions ineffective, and the amendment stood.⁷ The practical assumption is that once a state ratifies, the vote sticks.

Ratification Deadlines

Article V says nothing about how long states have to ratify. But in Dillon v. Gloss (1921), the Supreme Court held that Congress has implied authority to set a specific deadline, reasoning that ratification should reflect a contemporary national consensus rather than accumulated votes from different eras.⁸

Since the Eighteenth Amendment in 1917, Congress has attached a seven-year ratification deadline to nearly every proposed amendment, either in the text of the amendment itself or in the resolution’s preamble.⁹ If the deadline passes before thirty-eight states have ratified, the amendment fails.

The Equal Rights Amendment is the current test case. Congress proposed the ERA in 1972 with a seven-year deadline, later extended to 1982. The thirty-eighth state did not ratify until 2020, decades after the deadline expired. In 2020 and again in 2022, the Department of Justice’s Office of Legal Counsel concluded that the deadline was valid and enforceable, and that Congress could not retroactively remove or extend it without restarting the Article V process from the beginning. Federal courts have reached the same conclusion, and the Archivist has said the ERA cannot be certified under current legal authority.¹⁰

A few older amendments were sent to the states without any deadline attached and remain technically pending because they never formally expired.¹¹ The Twenty-Seventh Amendment came out of that same category: proposed in 1789 alongside the Bill of Rights and finally ratified by the thirty-eighth state on May 7, 1992, more than two centuries later.

Certification and Effective Date

When the thirty-eighth state ratifies, the Archivist of the United States reviews the official state notifications for legal sufficiency and issues a certificate identifying the ratifying states and declaring the amendment valid.¹² The Archivist’s role is ministerial. The amendment technically becomes part of the Constitution the moment the final required state ratifies, regardless of when the certificate is signed.

The certified amendment is published in the Federal Register and eventually printed in the United States Statutes at Large, which is the official legal record of federal law and constitutional amendments.¹² From that point on, it carries the same legal force as the original text of 1787.

One Permanent Limit

Article V places one boundary that cannot be crossed by any amendment: no state can be deprived of its equal representation in the Senate without its own consent. That protection sits outside the normal amendment process and holds even if every other state agrees.¹

Why So Few Amendments Succeed

The math explains most of it. Getting two-thirds of both chambers of Congress to agree on the same constitutional text is difficult in ordinary times and nearly impossible during periods of sharp political division. Even when a proposal clears Congress, thirty-eight states have to sign on, which means building support across very different political, cultural, and economic environments. Thirteen states can block any amendment, and they do not have to share a reason for their opposition.

That difficulty is the design. The framers wanted a Constitution that could change but not be rewritten on a wave of temporary enthusiasm. The twenty-seven amendments that have made it through, from the Bill of Rights to the abolition of slavery to expansions of the right to vote, reflect the kind of sustained national agreement the process was built to require.

1
National Archives. Article V, U.S. Constitution
2
Constitution Annotated | Congress.gov. ArtV.1 Overview of Article V, Amending the Constitution
3
Library of Congress. Proposals of Amendments by Convention
4
National Archives. Constitutional Amendment Process
5
Cornell Law Institute. Article V – Ratification by Conventions
6
Cornell Law School Legal Information Institute (LII). HAWKE v. SMITH, Secretary of State of Ohio
7
Cornell Law School. Article V – Effect of Prior Rejection of an Amendment or Rescission of Ratification
8
LII / Legal Information Institute. Congressional Deadlines for Ratification of an Amendment
9
Constitution Annotated | Congress.gov. Congressional Deadlines for Ratification of an Amendment
10
National Archives. Statement on the Equal Rights Amendment Ratification Process
11
Justia. Proposed Amendments Not Ratified by the States
12
National Archives. Acts and Resolutions