Subject matter jurisdiction (as opposed to personal jurisdiction) refers to the question of whether a particular court has the power or competence to decide the kind of controversy that is involved. (Friedenthal § 2.1) Note that subject matter jurisdiction is not an alternative to personal jurisdiction (the court's authority to enter a judgment binding on the particular defendant involved) but rather is an additional hurdle to be cleared. Fede In personam, (or personal jurisdiction) is the power of a court to adjudicate the personal legal rights of parties properly brought before it. Requires that the court not only have jurisdiction over the subject matter of the action, but also that it have jurisdiction over each party to the action. Due process of law requires appearance or service of process (notice of pendency of the lawsuit) before the defendant can be personally bound by any judgment. A person is subject to in personam jurisdiction on any of the foll

Personal jurisdiction means jurisdiction over the persons involved in the lawsuit, whether natural persons, corporations, or whatever, essentially the power to bring the parties before the court and bind them with its decisions. Subject matter jurisdiction is just what it sounds like -- power to deal with the subject matter of a law suit. Not all courts can handle all suits -- if you try to get a state court to take up, say, a question involving railroad employee pension rights, the court should refuse to hear it, since such matters belong exclusively to the federal courts. One notable and important difference between the two is that there are a lot of ways to waive the issue of personal jurisdiction, but no way to waive the question of subject matter jurisdiction. For example, if you're sued in a the court of another state from where you live, it's likely that that court will lack personal jurisdiction over you. However, if you think that you have some dynamite defense and file a pleading to say so, guess what -- you've just waived the personal jurisdiction issue. If the action does go forward, you're subject to the court's jurisdiction. (But most states have rules that will allow you to appear "specially" -- for the limited purpose of arguing not on the merits, but only that the action shouldn't be allowed for some reason, always an attractive possiblity in an overloaded court system.) On the other hand, the issue of subject matter jurisdiction never goes away, and neither the parties nor the court can waive it or agree to ignore it or stipulate to it or in any other way make it not an issue. If the court mistakenly hears and decides a case over which it lacked subject matter jurisdiction, its decision can be voided at any level of the appeal process at any time, and by either party, including the one who prevailed below.