Federal question jurisdiction is a term to refer to the situation in which a U.S. federal court has subject matter jurisdiction to hear a civil case because the plaintiff has alleged a violation of the Constitution, laws, or treaties of the United States.  Article III of the United States Constitution permits federal courts to hear such cases, so long as the United States Congress passes a statute to that effect.  However, an action arises under federal law only if federal law appears in the plaintiff’s own well-pleaded complaint.  The statute enacting federal question jurisdiction requires that the federal question must appear on the face of the plaintiff’s complaint.  Unlike diversity jurisdiction, a federal court can hear a federal question case even if no money is sought by the plaintiff.  The plaintiff cannot seek the jurisdiction of a federal court merely because it anticipates that the defendant is going to raise a defense based on the Constitution, or on a federal statute.