Courts within the federal judicial system:
- Federal district courts are courts of original jurisdiction. District courts, as all federal courts, are also courts of limited subject-matter jurisdiction, meaning that they have the authority to hear cases of a particular type or relating to a specific subject matter, primarily based on federal questions and diversity of parties. The statute for federal question jurisdiction, 28 U.S.C. § 1331, provides that the district courts have subject-matter jurisdiction in all civil actions arising under the Constitution, laws, and treaties of the United States. This jurisdiction is not exclusive; state courts also can hear claims based on federal law. The statute for diversity jurisdiction, 28 U.S.C. § 1332, provides the district courts jurisdiction in actions that meet two requirements: 1) complete diversity – no defendant is a citizen of the same state as any plaintiff, and 2) amount in controversy exceeds $75,000. Federal courts also have removal jurisdiction, which is the authority to try cases removed by defendants from state courts.
- Circuit courts are courts of appellate jurisdiction as they are authorized only to review decisions on appeal from district courts, certain specialized federal courts or federal administrative agencies. There are thirteen federal circuit courts; twelve for each one of the geographic circuits and one designated as the Federal Circuit which hears appeals from various specialized federal courts. Appeals from many of the administrative agencies are held in the Court of Appeals for the District of Columbia Circuit.
- United States Supreme Court has original jurisdiction over cases affecting ambassadors and actions in which states are parties. Its appellate jurisdiction over all other types of cases is mostly discretionary.
Courts within the state judicial system
- Courts of limited subject-matter jurisdiction are authorized to hear specific types of cases, such as small claims, traffic, landlord-tenant, or probate.
- Courts of original and general jurisdiction hear all cases not exclusively apportioned to courts of limited jurisdiction, such as state claims and federal questions that also could be brought in federal district courts. State courts of general jurisdiction are often at the county level, and vary in their designations, e.g., Superior Court in California, Circuit Court in Virginia, Court of Common Pleas in Ohio and Supreme Court in New York. In some states, courts of general jurisdiction also hold appellate jurisdiction over cases originally tried in courts of limited jurisdiction.
- Intermediate appellate courts exist only in more populous states. In some jurisdictions, the decision of the intermediate appellate court is final for most fact-bound and “routine” cases, such as domestic relations, and subject to discretionary appeal for constitutional questions.
- Courts of appellate jurisdiction are variously called the Supreme Court, the Court of Appeals, or, in Massachusetts, the Supreme Judicial Court, and have the authority to change decisions and rulings of lower courts. Depending on the case type and original decision, an appellate review may consist of an entirely new hearing (a trial de novo), a hearing whereby the appellate court gives deference to factual findings of the lower court, or a review of specific legal rulings of the lower court (an appeal on the record.) An appeal from the intermediate appellate court to this higher court is mostly by permission, with the exception of a small number of cases selected by legislatures, such as administrative law actions.
To decide a case, a court must have a combination of subject-matter jurisdiction (defined previously) and either personal jurisdiction (defined as having the power to render a judgment against a particular defendant) or territorial jurisdiction (defined as having the power to render a judgment involving events that occurred within a well-defined territory) along with adequate notice (a requirement that the parties be aware of the legal process affecting their rights, obligations and duties.)