Magistrate judges handle most of the pre-trial matters in the cases referred to them by the district judges. Magistrate judges make recommendations to the district judges regarding the cases referred to them. If all parties to a civil lawsuit so consent, they may have their case presided over from beginning to end by a magistrate judge. Senior judges are district judges who have reached a certain combination of age and years of service on the federal bench. Senior judges may preside over as many or as few cases as they so choose.
Senior status is meant to be a form of retirement or semi-retirement for district judges.
The chief judge is the administrative head of the court. Every seven years, a new chief judge is named based on seniority.