Writ of Certiorari, Explained

Losing in a federal court of appeals, or in a state's highest court, does not entitle anyone to another hearing before the Supreme Court. There is no appeal as of right for almost all cases that reach that level. Instead, the losing party files a petition asking the Court to take the case up, and the Court can simply decline. That petition is called a petition for a writ of certiorari, and the process of deciding whether to grant it is what lawyers mean when they talk about "seeking cert."

Where the power to review comes from

Congress, not the Constitution, gives the Supreme Court most of its certiorari jurisdiction. 28 U.S.C. § 1254 lets the Court review cases from the federal courts of appeals "by writ of certiorari granted upon the petition of any party to any civil or criminal case, before or after rendition of judgment or decree." 28 U.S.C. § 1257 does something similar for the highest court of a state, letting the Supreme Court step in when a final state judgment turns on the validity of a federal statute or treaty, the validity of a state law under the Constitution, or a federally based right, privilege, or immunity. Together, these two statutes are the main doors through which a case reaches the Court.

Getting through the door is a separate question from whether the Court wants to walk through it. Supreme Court Rule 10 states the standard bluntly: "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." The rule then lists what counts as a compelling reason, chiefly a conflict between federal appeals courts on the same legal question (a circuit split), a conflict between a state's highest court and a federal appeals court on an important federal question, or an important federal question that the Court has not yet settled. Rule 10 also warns that the Court rarely grants cert just to second-guess a lower court's factual findings or its application of a correctly stated legal rule to the facts of one case.

Why it is called the Rule of Four

Nine justices sit on the Court, but a case is not taken up by majority vote at the cert stage. By long-standing internal practice, it takes only four justices voting to grant review, not five. This is the Rule of Four. It is not written into Rule 10 or into Title 28 of the U.S. Code; it is a well-documented custom the Court itself has publicly described, not a quoted statute or rule provision. The practical effect is that a determined minority of the Court can force a case onto the docket, even though winning that case later still requires five votes.

Petitions are considered at private conferences, and most are denied without any opinion or explanation. A denial of certiorari is not a ruling on the merits. It leaves the lower court's decision in place, but it says nothing about whether the Supreme Court thinks that decision was correct.

How rarely the Court says yes

The numbers make the odds plain. As of 2026, uscourts.gov's public explanation of Supreme Court procedure states that the Court accepts 100 to 150 of the more than 7,000 cases it is asked to review each year, putting the overall grant rate in the low single digits.

That figure is worth pairing with a second, narrower number that measures something different: how many cases the Court actually argues and decides with a full opinion in a given term. In October Term 2023, the Court granted certiorari in roughly 62 cases and issued 60 signed opinions. Both figures are legitimate, but they are not counting the same thing. The uscourts.gov figure spans a full docket year and appears to include summary and per curiam dispositions along with fully briefed and argued cases, while the term-specific figure counts only merits opinions issued after full briefing and oral argument. Any single "how likely is cert" statistic should say which of these it is counting, since the difference between "cases the Court takes some action on" and "cases the Court hears argument in and decides" changes the picture considerably.

None of this makes certiorari arbitrary. It reflects a deliberate design: with a docket that could otherwise run into the thousands, Rule 10 lets the Court concentrate its limited argument calendar on the questions it says matter most, chiefly conflicts among lower courts and unsettled questions of federal law, rather than functioning as a general court of appeals for every losing litigant in the country.