In accordance with the Constitution, federal judges serve until they die, resign or are removed from office by the impeachment process. Since the impeachment process requires a trial by the United States Senate, and since the Constitutional provision concerning federal judges' tenure cannot be changed without the ratifications of three-fourths of the (now 50) states, federal judges have the best job security available in the United States.
However, the judges who preside over certain federal courts of limited jurisdiction are not life-tenured. Federal magistrates and bankruptcy judges, for example, are appointed for specified terms by the administrative bodies of the federal judiciary.
The chief judge is the judge in regular active service who is senior in commission of those judges who are (1) 64 years of age or under; (2) have served for one year or more as a judge; and (3) have not previously served as chief judge.
A U.S. magistratejudge is a judicial officer of the district court and is appointed by majority vote of the active district judges of the court to exercise jurisdiction over matters assigned by statute as well as those delegated by the district judges.
The number of magistratejudge positions is determined by the Judicial Conference of the United States, based on recommendations of the respective district courts, the judicial councils of the circuits, and the Director of the Administrative Office of the U.S. Courts.