Standing and Jurisdiction

Federal courts are courts of limited jurisdiction. Article III extends the judicial power only to certain cases and controversies, and Congress decides by statute which of those the lower courts may hear. The two most common bases are federal question jurisdiction, for cases arising under the Constitution, federal laws, or treaties, and diversity jurisdiction, for cases between citizens of different states where more than 75,000 dollars is at stake. Everything else belongs in state courts, which hear the vast majority of all lawsuits in the country.

Even within that jurisdiction, a plaintiff must have standing. Under Lujan v. Defenders of Wildlife in 1992, a plaintiff must show an injury in fact that is concrete and particular, that the injury is fairly traceable to the defendant's conduct, and that a court ruling is likely to redress it. Related doctrines require that a case be ripe, not premature, and not moot, meaning the dispute is still live. Courts also refuse to issue advisory opinions on hypothetical questions, a rule dating to the Court's refusal to advise George Washington in 1793.

These rules decide many of the most important cases before they reach the merits. In FDA v. Alliance for Hippocratic Medicine in 2024 the Supreme Court unanimously dismissed a challenge to the abortion pill mifepristone because the doctors bringing it lacked standing. Standing for states suing the federal government has expanded and contracted with litigation by both parties. In Trump v. CASA in 2025 the Court sharply limited universal injunctions, holding that federal courts generally may grant relief only to the parties before them.