Chief judges have administrative responsibilities with respect to their circuits, and preside over any panel on which they serve, unless the circuit justice (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, with seniority determined first by commission date, then by age. The chief judge serves for a term of seven years, or until age 70, whichever occurs first. If no judge qualifies to be chief, the youngest judge over the age of 65 who has served on the court for at least one year shall act as chief until another judge qualifies. If no judge has served on the court for more than a year, the most senior judge shall act as chief. Judges can forfeit or resign their chief judgeship or acting chief judgeship while retaining their active status as a circuit judge.
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 thirteen 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 but vacate their seats, thus allowing the U.S. President to appoint new judges to fill their seats.
^Knapp did not have a permanent seat on this court. Instead, he was appointed to the ill-fated United States Commerce Court in 1910 by William Howard Taft. Aside from their duties on the Commerce Court, the judges of the Commerce Court also acted as at-large appellate judges, able to be assigned by the Chief Justice of the United States to whichever circuit most needed help. Knapp was assigned to the Second Circuit upon his commission.
^Gurfein was nominated for a seat on the Second Circuit by President Nixon, but he was confirmed after Nixon's resignation and was appointed to the Second Circuit by (i.e., received his commission from) President Ford.