Explainer · Supreme Court

How the Supreme Court Picks Its Cases, and How Its Rulings Work

Last reviewed: September 26, 2026

Short answer: The Supreme Court chooses almost all of its cases. A losing party asks the Court for a writ of certiorari, and four of the nine justices must vote to take the case. The Court accepts 100 to 150 of the more than 7,000 cases it is asked to review each year. After written briefs and oral argument, the justices vote in a private conference, and one justice in the majority writes the opinion of the Court.

Where the Court’s power comes from

Article III vests “the judicial Power of the United States” in “one supreme Court” and lower courts that Congress creates. That power extends to “Cases” and “Controversies,” meaning real disputes, not abstract questions. Judges “shall hold their Offices during good Behaviour,” and their pay cannot be cut while they serve.

The Court has original jurisdiction, where it is the first and only court to hear a case, in a narrow set of disputes, such as those between states. Most of its work is appellate: reviewing decisions from a U.S. court of appeals or from a state’s highest court when a federal question is involved.

Step 1: The petition for certiorari

A party unhappy with a lower-court decision files a petition asking the Court to order the lower court to send up the record. The Court’s Rule 10 is blunt: “Review on a writ of certiorari is not a matter of right, but of judicial discretion. A petition for a writ of certiorari will be granted only for compelling reasons.”

Rule 10 lists the kinds of reasons that count:

• federal appeals courts, or state high courts, have split on the same important question;
• a lower court has decided an important federal question that the Court has not settled but should; or
• a lower court has decided a federal question in a way that conflicts with the Supreme Court’s own decisions.

The same rule warns that a petition “is rarely granted when the asserted error consists of erroneous factual findings or the misapplication of a properly stated rule of law.” The Court is not there to correct every mistake.

Step 2: The rule of four

Every justice may read each petition, but many take part in what is informally known as the “cert pool”: petitions are divided among the participating justices, whose law clerks each write a short memo with a recommendation on whether to take the case. Under the Court’s rules, four of the nine justices must vote to accept a case. Emergency relief works differently: five votes are needed to grant a stay, such as a stay of execution.

Step 3: Briefs and oral argument

Once a case is granted, the parties file written briefs, and outside groups may file “friend of the court” (amicus curiae) briefs. By law, the Court’s term begins on the first Monday in October, and the Court usually recesses from late June or early July. At oral argument, each side typically has about 30 minutes. The petitioner argues first and may reserve time for rebuttal. The Solicitor General usually argues when the federal government is a party.

Step 4: Conference, the vote and the opinion

The justices discuss argued cases in private conference. The Chief Justice speaks first, then each justice in descending order of seniority, and votes are cast in the same order. The Chief Justice, or the most senior justice in the majority if the Chief Justice dissents, assigns a justice in the majority to write the opinion of the Court. The most senior dissenting justice can assign the main dissent. A justice who agrees with the result but not the reasoning may write a concurring opinion.

For how rulings play out in practice, see our explainers on executive orders and court review and on the 2026 tariff ruling, and follow our Supreme Court coverage.