How Many Seats Are on the Supreme Court—and Can It Change?

The U.S. Supreme Court has nine seats: one Chief Justice and eight Associate Justices. That number is set by federal statute, not the Constitution, and it has stood at nine since 1869. Congress has the power to change it and has done so seven times in American history.

The governing law is short. Under 28 U.S.C. § 1, the Supreme Court consists of a Chief Justice and eight Associate Justices.¹ Each justice casts one vote, and the odd total helps avoid ties.

The Nine Justices Currently Serving

The current bench is Chief Justice John G. Roberts Jr. and Associate Justices Clarence Thomas, Samuel A. Alito Jr., Sonia Sotomayor, Elena Kagan, Neil M. Gorsuch, Brett M. Kavanaugh, Amy Coney Barrett, and Ketanji Brown Jackson.²

Why the Constitution Does Not Fix the Number

Article III, Section 1 creates “one supreme Court” and says nothing about how many justices should sit on it.³ Decisions about the court’s size and organization were left to Congress.⁴ There is no constitutional floor or ceiling on how many seats the court can have.

How the Number Has Changed Before

Congress has resized the court seven times since 1789, often alongside changes to the federal circuit courts and often with political motives in play. The count did not climb steadily to nine. It bounced between six and ten before settling.

1789 — six seats. The Judiciary Act of 1789 created the court with a Chief Justice and five Associate Justices.⁵
1801 — five seats. Congress reduced the number to five, but no vacancy occurred before the law was repealed in 1802 and the count returned to six.⁶
1807 — seven seats. A seventh seat was added with the new Seventh Circuit.⁶
1837 — nine seats. Two more justices were added when the Eighth and Ninth Circuits were created for newly admitted western states.⁶
1863 — ten seats. During the Civil War, Congress added a tenth justice along with the Tenth Circuit.⁶
1866 — gradual reduction to seven. Congress ordered the court to shrink through attrition, in part to keep President Andrew Johnson from filling any seats.⁶
1869 — nine seats, where it stands today. After Johnson left office, Congress expanded the court back to nine, and it has stayed there ever since.⁶

Circuit growth gave Congress a tidy legal justification for most of these moves, but the timing often tracked political fights over the presidency.

Could the Number Change Again

Yes. Because the nine-seat figure sits in an ordinary statute, Congress can change it the same way it passes any other law: a bill through the House and Senate, then the President’s signature. A veto can be overridden by two-thirds of each chamber.

The practical obstacle is the Senate filibuster. Most legislation needs 60 votes to end debate and move to a final vote, not a simple majority.⁷ The Senate carved out exceptions for judicial nominations in the 2010s, but those exceptions do not apply to legislation. A bill to add or remove seats would face the full 60-vote threshold unless the Senate first changed its own rules.

One historical attempt is worth knowing. In 1937, President Franklin D. Roosevelt proposed the Judicial Procedures Reform Bill, which would have let him appoint one additional justice for every sitting justice over 70, up to six new seats, potentially bringing the court to 15.⁸ The Senate Judiciary Committee called the bill “an invasion of judicial power such as has never before been attempted in this country,” and the Senate shelved it by July 1937. The nine-seat count has held through every proposal since.

What Happens When Seats Are Vacant

Authorized seats and sitting justices are not always the same thing. Vacancies, illnesses, and recusals can thin the bench. Federal law requires a quorum of six justices to hear a case and issue a binding decision.¹

If the court falls below six, the response depends on how a case got there. For cases on direct appeal from a federal district court, the Chief Justice can send the case to the relevant federal appeals court for final decision. For other cases, if the remaining justices expect the shortage to carry into the next term, the court affirms the lower court’s ruling by default.⁹ That affirmance leaves the lower decision in place without creating national precedent, and the underlying legal question waits for a future case before a full court.

1
Office of the Law Revision Counsel. 28 USC 1 – Number of Justices; Quorum
2
Supreme Court of the United States. Justices
3
Congress.gov. U.S. Constitution – Article III
4
Cornell Law School. Congressional Power to Establish the Supreme Court
5
United States Courts. About the Supreme Court
6
Constitution Annotated. ArtIII.S1.8.3 Supreme Court and Congress
7
U.S. Senate. About Filibusters and Cloture
8
Federal Judicial Center. FDR’s “Court-Packing” Plan
9
Office of the Law Revision Counsel. 28 USC 2109 – Quorum of Justices