Glossary
Writ of certiorari
The order by which the Supreme Court agrees to review a lower court's decision, granted at the justices' discretion.
Also called: cert, cert petition, certiorari
A writ of certiorari, usually shortened to "cert," is how most cases reach the U.S. Supreme Court. A party that lost in a federal appeals court or a state's highest court files a petition asking the Court to hear the case. If the Court agrees, it "grants cert"; if not, it "denies cert" and the lower ruling stands.
Review is discretionary. Under the informal "rule of four," the votes of four of the nine justices are enough to grant a petition. The Court receives thousands of petitions a year and hears only a small fraction. It is most likely to take cases in which federal appeals courts disagree (a circuit split), a lower court has struck down a federal law, or an issue of national importance is at stake. A denial does not mean the Court agrees with the lower court's decision.
Interest groups file amicus briefs urging the Court to grant or deny review. Cases decided after full briefing and argument make up the "merits docket," as distinct from emergency orders on the shadow docket.
Last reviewed November 8, 2026