A supermajority in Congress is any vote threshold higher than a simple majority, and it applies whenever the Constitution or Senate rules demand broader agreement than 51% before Congress can act. The two thresholds you will encounter are two-thirds, used for the Constitution’s most consequential actions, and three-fifths, used in the Senate to cut off debate.
What the Numbers Actually Are
A regular bill passes the House with 218 of 435 votes and the Senate with 51 of 100.1house.gov. The Legislative Process A supermajority raises that bar. Two-thirds of a full Senate is 67 votes; two-thirds of a full House is 290. Three-fifths of the Senate is 60.
The exact math shifts depending on how the threshold is worded. Some provisions require two-thirds of “members present,” which can drop the number needed when seats are vacant or senators are absent. Others require two-thirds of members “duly chosen and sworn,” which locks the calculation to the full membership.
When the Constitution Requires Two-Thirds
Several of the most serious actions Congress can take are set at two-thirds by the Constitution itself. These thresholds cannot be lowered by ordinary legislation or by a chamber changing its rules.
Overriding a Presidential Veto
If the President vetoes a bill, Congress can still enact it, but only with a two-thirds vote in both the House and the Senate.2Congress.gov. Constitution Annotated – Article I, Section 7, Clause 2 Assembling 290 House votes and 67 Senate votes typically requires bipartisan support, which is why successful overrides are uncommon.
Proposing Constitutional Amendments
Two-thirds of both chambers must vote to propose an amendment before it can go to the states for ratification.3Congress.gov. Constitution Annotated – Article V Article V also allows two-thirds of state legislatures to call a convention for proposing amendments, though that route has never been used.
Ratifying Treaties
Treaties negotiated by the President take effect only when two-thirds of the senators present concur.4Congress.gov. Constitution Annotated – Article II, Section 2, Clause 2 The House has no role in treaty ratification.
Expelling a Member of Congress
Each chamber can expel one of its own members by a two-thirds vote.5Congress.gov. Constitution Annotated – Article I, Section 5, Clause 2 Expulsion permanently removes the member. A censure, which is a formal expression of disapproval that does not remove the member, needs only a simple majority.
Deciding a Presidential Disability Dispute
Under the Twenty-Fifth Amendment, if the Vice President and a majority of the Cabinet declare the President unable to serve and the President disputes that finding, Congress decides. Keeping the Vice President in an acting role requires two-thirds of both chambers within 21 days; otherwise the President resumes power.6Congress.gov. Constitution Annotated – Twenty-Fifth Amendment This provision has never been invoked.
Lifting the Fourteenth Amendment’s Insurrection Bar
Section 3 of the Fourteenth Amendment bars anyone who took an oath to support the Constitution and then engaged in insurrection from holding federal or state office. Only a two-thirds vote of each chamber can remove that disability.7Congress.gov. Constitution Annotated – Fourteenth Amendment, Section 3
Impeachment Uses Two Different Thresholds
Impeachment is often described as a single event, but it involves two votes at two different bars. The House holds the sole power to impeach, meaning to formally charge an official with misconduct, and that vote requires only a simple majority.8Congress.gov. Constitution Annotated – Overview of Impeachment
The Senate then holds the trial, and conviction (which removes the official from office) requires two-thirds of the senators present.9Congress.gov. Constitution Annotated – Article I, Section 3 When the President is being tried, the Chief Justice of the United States presides. No president has ever been convicted by the Senate.
The Senate’s 60-Vote Rule
The most talked-about supermajority in Congress is not in the Constitution. It comes from Senate Rule XXII, which governs cloture, the procedure for ending debate and breaking a filibuster. On most legislation, invoking cloture requires three-fifths of all senators duly chosen and sworn, which is 60 votes in a fully seated Senate.10Congress.gov. Invoking Cloture in the Senate
Once cloture passes, debate is limited to 30 more hours before a final vote.11U.S. Government Publishing Office. United States Senate Manual 110th Congress – Rule XXII Passing the bill itself still needs only 51 votes. The practical result is that 41 senators can block almost any bill by refusing to end debate, which is why commentators say a bill needs “60 votes to pass the Senate” even though the Constitution only requires a simple majority.
When 60 Votes Are Not Required
The Senate has created exceptions where the 60-vote cloture threshold does not apply.
Budget Reconciliation
Under budget reconciliation, debate is capped at 20 hours, so there is no filibuster to break and the bill can pass with 51 votes.12Congress.gov. The Senate’s Byrd Rule: Frequently Asked Questions The 2017 tax law and the 2010 health care law both moved through reconciliation.
The catch is scope. Reconciliation bills have to deal with spending, revenues, or the debt limit, and the Byrd Rule blocks “extraneous” provisions with no budgetary effect, provisions that raise deficits outside the reconciliation window, or changes to Social Security.12Congress.gov. The Senate’s Byrd Rule: Frequently Asked Questions Waiving a Byrd Rule point of order takes 60 votes, so reconciliation is powerful but limited.
Presidential Nominations
Nominations used to face the same 60-vote cloture bar as legislation. In November 2013, the Senate reinterpreted Rule XXII to allow cloture on executive and judicial nominations below the Supreme Court to be invoked by simple majority. In April 2017, the Senate extended that precedent to Supreme Court nominations.13Rules.senate.gov. Senate Procedures to Confirm Nominees Every presidential nomination now advances and is confirmed by simple majority. Ordinary legislation still needs 60 votes to overcome a filibuster.