Subject-matter jurisdiction must be distinguished from personal jurisdiction, which is the power of a court to render a judgment against a particular defendant, and territorial jurisdiction, which is the power of the court to render a judgment concerning events that have occurred within a well-defined territory. Unlike personal or territorial jurisdiction, lack of subject-matter jurisdiction cannot be waived. A judgment from a court that did not have subject-matter jurisdiction is forever a nullity.
To decide a case, a court must have a combination of subject (subjectam) and either personal (personam) or territorial (locum) jurisdiction.
Subject-matter jurisdiction, personal or territorial jurisdiction, and adequate notice are the three most fundamental constitutional requirements for a valid judgment.
By far the most important two categories of federal subject-matter jurisdiction are federal question jurisdiction and diversity jurisdiction. The enabling 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, or treaties of the United States. As mentioned before, this jurisdiction is ordinarily not exclusive; states too can hear claims based on federal law. The enabling statute for diversity jurisdiction, 28 U.S.C. § 1332, grants the district courts jurisdiction in an action that meets two basic conditions:
Federal courts also have removal jurisdiction, which is the authority to try cases removed by defendants from state courts. The contours of removal jurisdiction are almost identical to those of original jurisdiction. See removal jurisdiction for more information.
According to the Federal Rules of Civil Procedure, a federal court may dismiss a case for lack of subject-matter jurisdiction upon motion of a party or sua sponte, upon its own initiative.