The U.S. Courts of Appeals: Background and Circuit Splits from 2025

The U.S. Courts of Appeals frequently act as the final arbiters of questions of law within their respective jurisdictions. Although the Supreme Court of the United States sits at the pinnacle of the American judicial system and acts as the final arbiter on questions of federal law, the number of precedential decisions issued each year by the Court is quite small. For example, in both of its two most recently concluded terms, the 2023 and 2024 Terms, the Court issued final decisions in 68 argued cases, 64 through signed opinions and the remainder through per curiam opinions. By contrast, the courts that sit just below the Supreme Court in the federal judicial hierarchy—the U.S. Courts of Appeals for 13 “circuits”—issue thousands of precedential decisions every year. The most current data available from the U.S. Courts reveal that in FY2024 and FY2023, the appellate courts for the 12 “regional” circuits (i.e., all of the federal courts of appeals other than the U.S. Court of Appeals for the Federal Circuit) published, respectively, 3,369 and 3,325 precedential opinions disposing of appeals to those courts. This state of affairs is a product of both the design and the historical evolution of the federal judiciary. With limited exceptions, the Supreme Court exercises wholly discretionary appellate jurisdiction, deciding for itself which appeals it will accept out of the thousands that are submitted for its consideration each year. The federal courts of appeals, by contrast, are statutorily obligated to accept and decide all appeals challenging a final decision of a federal trial court, as well as certain appeals challenging non-final orders. What is more, in the absence of a binding Supreme Court decision on an issue, each federal court of appeals is free to decide that issue independently, and its decision will then be binding on all federal trial courts within the jurisdiction of that circuit. As a result, the federal appellate courts can, and often do, reach different conclusions on the same issue of federal law, causing a “split” among the circuits that leads to the non-uniform application of federal law among similarly situated litigants. These conflicts may then be locked into place due to the judge-made “law of the circuit doctrine,” which all of the federal courts of appeals have adopted. Under this doctrine, the first published decision on a question of federal law by a three-judge panel within a circuit—including one diverging from a decision in another federal court of appeals—is generally binding on all later panels within that same circuit unless the decision is reviewed and overruled by the Supreme Court or a later (usually en banc) appellate panel within that circuit, or is superseded by a legislative change in the governing law. The U.S. Courts of Appeals play a pivotal role in shaping federal law. Their decisions often determine how statutes and constitutional provisions apply in practice, particularly when the Supreme Court declines review. Because these rulings bind all district courts within a circuit and frequently diverge across circuits, they can create lasting differences in the interpretation and application of federal law nationwide. In 2025, more than 100 circuit splits emerged or widened and remain unresolved as of this report. Congress is constitutionally empowered to respond legislatively to many of these decisions, and may amend to clarify statutory provisions that courts interpret differently across the country.