How the U.S. Constitution amendment process works comes down to two steps set out in Article V: a proposal stage that requires a two-thirds vote in both houses of Congress (or a convention called by two-thirds of the state legislatures), and a ratification stage that requires approval from three-fourths of the states. Since 1787, more than 11,000 amendments have been introduced in Congress, 33 cleared the proposal threshold, and only 27 completed ratification. The framers built the difficulty in on purpose.
Step One: Proposing an Amendment
The Congressional Route
Almost every amendment has started in Congress. Both the House and the Senate must approve identical text by a two-thirds vote. That threshold applies to the members present and voting, assuming a quorum, not to the full membership of each chamber. The proposal moves as a joint resolution containing the amendment’s exact wording and specifying which ratification method the states will use. All 27 ratified amendments took this path.
The State Convention Route
Article V also gives states a way to force the issue without waiting for Congress. If two-thirds of state legislatures (currently 34 of 50) submit formal applications, Congress must call a national convention to propose amendments. This has never happened. Because no convention has ever been held, basic procedural questions are unresolved: how delegates would be chosen, whether states would vote equally or by population, and whether a convention could be confined to a single topic.
The route still matters as leverage. When state legislatures were close to forcing a convention on direct election of senators, Congress proposed what became the 17th Amendment itself.
Step Two: Ratifying an Amendment
State Legislatures
A proposed amendment becomes part of the Constitution when three-fourths of the states (38 of 50 today) ratify it. The default method sends the proposal to each state’s legislature for a vote. Twenty-six of the 27 ratified amendments went this way. Neither the Constitution nor federal law dictates whether a simple majority or a supermajority is needed inside the state legislature; that is left to each state’s own rules.
State Ratifying Conventions
Congress can instead direct that states ratify through specially convened conventions of elected delegates. This has happened once, for the 21st Amendment repealing Prohibition in 1933. Repeal supporters chose the convention method because they believed state legislatures, heavily lobbied by temperance groups, would be less receptive. Thirty-six state conventions ratified within a year. There is no federal template for organizing these conventions, so each state ran its own process.
The President Is Not Part of This
The President has no formal role. No signature is required, and there is no veto. The Supreme Court settled the point in Hollingsworth v. Virginia (1798), where Justice Chase wrote that the President’s veto power “applies only to the ordinary cases of legislation: He has nothing to do with the proposition, or adoption, of amendments to the Constitution.” The process moves entirely through Congress and the states.
Certification by the National Archives
Once Congress approves a joint resolution, it goes to the Office of the Federal Register at the National Archives, which publishes the official text and prepares an information package for the states. The Archivist of the United States notifies each governor, who submits the amendment to the legislature (or calls a convention when Congress specified that method). As each state ratifies, it returns a certified copy of its action to the Archivist. When the 38th state ratifies, federal law directs the Archivist to “forthwith cause the amendment to be published, with his certificate.” The word “forthwith” makes the duty mandatory. The Archivist certifies the paperwork; the Archivist does not judge whether the states got the substance right.
Ratification Deadlines
Article V says nothing about timing. Congress began attaching seven-year deadlines to proposed amendments in the early 20th century, and the Supreme Court upheld the practice in Dillon v. Gloss (1921), reading Article V to require ratification “within some reasonable time after the proposal.”
Deadlines can be decisive. The Equal Rights Amendment carried a seven-year deadline when Congress proposed it in 1972. Congress extended it to 1982, and the amendment fell short. Three more states voted to ratify after the deadline, bringing the total to 38, but the Archivist has not certified the ERA. In December 2024, the National Archives stated that the ERA “cannot be certified as part of the Constitution due to established legal, judicial, and procedural decisions,” pointing to Justice Department opinions that the original deadline still applies.
When there is no deadline, an amendment can wait a very long time. The 27th Amendment, which concerns congressional pay, was proposed in 1789 and ratified in 1992.
Can a State Take Back Its Ratification?
The law is unsettled. During ratification of the 14th Amendment in 1868, New Jersey and Ohio tried to rescind, and Congress counted them anyway and declared the amendment adopted. In Coleman v. Miller (1939), the Supreme Court treated rescission as a “political question” for Congress rather than the courts. Five states attempted to rescind their ERA ratifications between 1973 and 1978. A federal district court in Idaho ruled in 1981 that rescission was valid, but the Supreme Court vacated that ruling as moot once the ERA’s deadline passed. The question remains open.
What Cannot Be Changed
Article V originally shielded two subjects from amendment until 1808: the clauses protecting the importation of enslaved people and the requirement that direct taxes be apportioned among the states by population. Those limits expired on schedule.
One restriction is permanent. No state can be deprived of its equal representation in the Senate without its own consent. That is the only provision of the Constitution that is essentially unamendable by its own terms.
Why the Process So Rarely Succeeds
Of the 33 amendments Congress has ever proposed, six went to the states and were never ratified. Four of those remain technically pending because Congress attached no deadline: the Congressional Apportionment Amendment (1789), the Titles of Nobility Amendment (1810), the Corwin Amendment (1861), and the Child Labor Amendment (1924). The other two, the ERA and the D.C. Voting Rights Amendment, expired.
The two-thirds and three-fourths thresholds are the point of the design. Changing the Constitution takes sustained agreement across regions and political factions, and amendments that succeed usually reflect a national consensus that has already formed.