The Supreme Court sits at the top of the federal judiciary and decides questions of federal law and the Constitution for the whole country. Unlike most courts, it chooses nearly all of its cases. A small number arrive under its original jurisdiction, such as disputes between states, but almost all come on appeal from federal circuit courts or state supreme courts.
This guide follows a case from the moment a losing party asks for review to the day the Court announces its decision, and explains the emergency docket that increasingly shapes the Court's work.
Once review is granted, each side files a written brief setting out its arguments, followed by a reply. Outside parties, including interest groups, states, scholars, and the federal government, may file amicus curiae, or friend of the court, briefs, and major cases attract dozens. The Solicitor General, who represents the United States before the Court, files in many cases even when the government is not a party and is often invited to give the government's views.
Most federal cases begin in one of 94 district courts and are appealed to one of 13 circuit courts. The losing party may then file a petition for certiorari, usually within 90 days. To be heard, a case must present a real dispute, and the person bringing it must have standing, a concrete injury the courts can remedy. If four justices vote to grant the petition, the case is placed on the docket. A denial leaves the lower court ruling in place and sets no precedent.
The Court hears arguments from October through April, usually giving each side 30 minutes, though major cases often run longer. Since 2020 the justices have added a round in which each asks questions in turn by seniority. Within days, the justices meet alone in conference, with no clerks or staff present, to discuss and vote, beginning with the Chief Justice. The most senior justice in the majority assigns who writes the opinion, which drafts and circulates for months as justices join, write concurrences, or dissent.
Decisions are announced from the bench and posted online, with the busiest weeks in June. The majority opinion becomes binding precedent, while concurrences and dissents explain other views and sometimes shape later law. The Court rarely overrules itself, following the principle of stare decisis, but it does, as when Loper Bright v. Raimondo in 2024 overruled the Chevron doctrine that had governed review of agency interpretations for forty years.
Not every important ruling follows the full process. Parties can ask the Court for emergency relief, such as a stay of a lower court order, and these applications are often decided within days, sometimes with little or no explanation. Since 2025 a large number of challenges to executive actions have reached the Court this way. Supporters say quick action is necessary when policies of national reach are blocked, while critics say major questions are being decided without full briefing and argument. When the public or Congress objects to the Court's decisions, responses range from constitutional amendments and new laws to proposals to expand the Court or limit its jurisdiction.
Article III created one Supreme Court and left its size to Congress, which has fixed it at nine justices since 1869: a Chief Justice and eight associate justices, all appointed for life. The Court's most important power, judicial review, the authority to strike down laws that conflict with the Constitution, was established in Marbury v. Madison in 1803. Its decisions bind all lower courts on questions of federal law.
See how the Court picks its cases in which cases make it to the Supreme Court, follow a full year in a year at the Supreme Court, or learn to read the result in how to read a Supreme Court opinion.