A writ of certiorari is an order from a higher court telling a lower court to send up the record of a case for review, and in modern U.S. practice it is the mechanism the Supreme Court uses to pick which cases it will hear. The Court receives more than 7,000 petitions each term and agrees to decide roughly 1% of them. Review is entirely discretionary. Losing in the court below does not entitle anyone to Supreme Court review; a party has to ask for it, and the justices have to agree the case is worth their time.
The word itself comes from Latin, loosely meaning “to be more fully informed.”1Legal Information Institute. Writ of Certiorari Congress gave the Supreme Court its current discretionary posture through the Judiciary Act of 1925, which stripped away most of the Court’s mandatory jurisdiction and replaced it with cert review.2Federal Judicial Center. Landmark Legislation: The Judges’ Bill Two statutes set the Court’s reach today. Under 28 U.S.C. § 1254, it can review decisions from any federal court of appeals on cert.3Office of the Law Revision Counsel. 28 US Code 1254 Under 28 U.S.C. § 1257, it can review final judgments from a state’s highest court when the case turns on a federal statute, treaty, or constitutional provision.4Office of the Law Revision Counsel. 28 US Code 1257
What the Court Looks For
The justices do not grant certiorari just because the lower court may have been wrong. Rule 10 of the Supreme Court’s rules lists the kinds of reasons that actually move the Court, and all of them concern systemic problems rather than one litigant’s misfortune.5Legal Information Institute. Rule 10 – Considerations Governing Review on Writ of Certiorari
The strongest basis is a circuit split: two or more federal appeals courts have reached conflicting conclusions on the same legal question, so the law effectively means different things in different parts of the country. A split between a state high court and a federal appeals court on the meaning of federal law carries similar weight. The Court also considers whether a lower court has decided an important federal question it has never addressed, or has strayed so far from normal judicial procedure that the Court’s supervisory power needs to step in. Rule 10 warns that cert will be granted “only for compelling reasons,” and a petition that cannot point to at least one of these factors rarely gets anywhere.
Filing the Petition
The petition has a fixed structure. It opens with the “Questions Presented,” which identify the exact legal issue the petitioner wants resolved. Vague or sprawling questions tend to sink a petition early. The document then includes a corporate disclosure statement (if the petitioner is a business), a table of authorities, the history of the case through the final lower-court ruling, and an argument for why the question matters beyond the dispute at hand. An appendix with the full text of the lower court’s opinion and the challenged order is mandatory; leaving it out is one of the fastest routes to rejection by the Clerk’s office.
Petitions filed in booklet format are capped at 9,000 words, footnotes included.6Legal Information Institute. Rule 33 – Document Preparation The questions presented, corporate disclosures, table of contents, and table of authorities do not count against the limit. A justice can authorize more words, but the rules say such requests are “not favored.”
Deadlines
The petition must reach the Clerk within 90 days after entry of the lower court’s final judgment, measured from the date of entry rather than any later written mandate. If either side filed a timely rehearing petition below, the 90-day clock runs instead from the date rehearing was denied or, if granted, from the new judgment.7Legal Information Institute. Rule 13 – Review on Certiorari: Time for Petitioning
A single justice can extend the deadline by up to 60 days for good cause, but the application must be filed at least 10 days before the original deadline and must give specific reasons. The rules describe extension requests as “not favored.”
Fees and Copies
A $300 docket fee accompanies a paid filing. Petitioners who cannot afford it may move to proceed in forma pauperis, supported by a notarized affidavit of indigency. If the lower court already appointed counsel for an indigent party, the affidavit requirement is waived, but the motion must cite the authority under which counsel was appointed.8Supreme Court of the United States. 2026 Rules of the Court – Rule 39
Paid petitions require 40 printed copies in the Court’s booklet format. Parties represented by counsel also submit the petition through the Court’s electronic filing system, which supplements rather than replaces the paper copies. In forma pauperis filers submit an original and 10 copies.9Supreme Court of the United States. 2026 Rules of the Court – Rule 12.2
The Respondent’s Opposition
Once the petition is docketed, the opposing party has 30 days to file a brief in opposition. An opposition is not required in most cases, with capital cases the main exception. Skipping it still carries risk: any objection based on what happened in the proceedings below can be treated as waived if it is not raised in the opposition brief.10Legal Information Institute. Rule 15 – Briefs in Opposition; Reply Briefs; Supplemental Briefs A respondent with nothing to say can file an express waiver, which speeds distribution to the justices. In high-stakes cases most respondents do file; letting the petitioner’s framing stand unchallenged is a gamble experienced litigators tend to avoid.
How the Justices Decide
No justice reads every petition personally. Most participate in the “cert pool,” where clerks from the participating chambers divide the petitions and write summary memos recommending whether a case deserves full attention.11Legal Information Institute. Certiorari Those memos go to each justice before the Court’s private conferences.
At conference, the justices discuss only cases placed on a “discuss list.” Most petitions never make it that far, which is itself a form of triage. For the ones that do, the Court applies the Rule of Four: if at least four of the nine justices vote to hear a case, cert is granted. The threshold is deliberately lower than a majority, so a minority of the Court can bring a significant issue to the full bench even when five justices would prefer to pass.
Amicus Briefs at the Petition Stage
Outside parties with a stake in the legal question can file amicus curiae (“friend of the court”) briefs before the Court decides whether to take the case. An amicus brief supporting the petitioner is due within 30 days after the case is docketed or after the Court calls for a response, whichever is later. Briefs supporting the respondent follow the same window as the opposition brief. The amicus must notify all parties’ counsel of its intent to file at least 10 days before the brief is due.12Supreme Court of the United States. 2023 Rules of the Court – Rule 37
The Court’s rules are direct about what helps and what doesn’t: a brief that brings relevant information the parties have not raised “may be of considerable help,” while one that merely repeats arguments already made “burdens the Court, and its filing is not favored.” A wave of amicus filings from industry groups, civil rights organizations, or state attorneys general can also signal to the justices that a legal question has broad real-world consequences, which itself feeds into the decision to grant or deny.
What Happens After the Court Decides
If Certiorari Is Denied
Most petitions end with a one-line order: “certiorari denied.” The lower court’s ruling stands, but the denial carries no endorsement of its reasoning. It means only that the justices chose not to spend docket space on the case.
A petitioner who thinks the denial was wrong has one narrow option: a petition for rehearing, filed within 25 days of the denial. That deadline cannot be extended for any reason. The grounds are limited to intervening events of substantial importance or other compelling reasons unavailable when the original petition was filed, and counsel must certify that the rehearing petition is brought in good faith and not for delay.13Legal Information Institute. Rule 44 – Rehearing These petitions almost never succeed.
If Certiorari Is Granted
A grant moves the case into full merits briefing. Both sides prepare detailed written arguments, and the Court schedules oral argument where the justices question counsel directly. The lower court’s judgment is effectively on hold during this period. The case ends with a written opinion that becomes binding law across the country, resolving the split or federal question that prompted the Court to take the case in the first place.