Chief judges have administrative responsibilities with respect to their circuits, and preside over any panel on which they serve unless the circuit justice (i.e., the Supreme Court justice responsible for the circuit) is also on the panel. Unlike the Supreme Court, where one justice is specifically nominated to be chief, the office of chief judge rotates among the circuit judges. To be chief, a judge must have been in active service on the court for at least one year, be under the age of 65, and have not previously served as chief judge. A vacancy is filled by the judge highest in seniority among the group of qualified judges. The chief judge serves for a term of seven years or until age 70, whichever occurs first. The age restrictions are waived if no members of the court would otherwise be qualified for the position.
When the office was created in 1948, the chief judge was the longest-serving judge who had not elected to retire on what has since 1958 been known as senior status or declined to serve as chief judge. After August 6, 1959, judges could not become or remain chief after turning 70 years old. The current rules have been in operation since October 1, 1982.
The court has six seats for active judges, numbered in the order in which they were initially filled. Judges who assume senior status enter a kind of retirement in which they remain on the bench, while vacating their seats, thus allowing the U.S. President to appoint new judges to fill their seats.
^"Court Calendar". United States Court of Appeals for the First Circuit. Retrieved October 26, 2012. In January through June, and October through December, the Court usually sits for one week starting on the first Monday of the month. In either July or August, the court sits for one week. In September, the Court starts on the Wednesday after Labor Day and sits for the 3 days in that week and the 5 days in the following week. In November and March the court sits two weeks, with one week in Boston and one week in Puerto Rico. Court sittings are held in the morning, typically between 9:30 a.m. and 1:00 p.m.