En banc, in banc, in banco or in bank is a French term (meaning "on a bench") used to refer to the hearing of a legal case where all judges of a court will hear the case (an entire "bench"), rather than a panel of them. It is often used for unusually complex cases or cases considered to be of greater importance. Appellate courts in the United States sometimes grant rehearing en banc to reconsider a decision of a panel of the court (a panel generally consisting of only three judges) where the case concerns a matter of exceptional public importance or the panel's decision appears to conflict with a prior decision of the court. In rarer instances, an appellate court will order hearing en banc as an initial matter, instead of the panel hearing it first.
Some appellate courts, such as the Supreme Court of the United States and the highest courts of most U.S. states, do not sit in panels, but hear all of their cases en banc (with the exception of cases where a judge is ill or recused).
United States Courts of Appeals
Cases in United States Courts of Appeals are heard by a three-judge panel. A majority of the active circuit judges may decide to hear or rehear a case en banc. Parties may suggest an en banc hearing to the judges, but have no right to it. Federal law states en banc proceedings are disfavored but may be ordered in order to maintain uniformity of decisions within the circuit or if the issue is exceptionally important. Fed. R. App. P. 35(a). Each court of appeals also has particular rules regarding en banc proceedings. Only a court sitting en banc or the Supreme Court of the United States can overrule a prior decision in that circuit; in other words, one panel cannot overrule another.
states that for courts with more than 15 judges, an en banc hearing may consist of "such number of members of its en banc courts as may be prescribed by rule of the court of appeals." So far, only the United States Court of Appeals for the Ninth Circuit, with 29 judges, utilizes that procedure, and its en banc court consists of 11 judges. Theoretically, the Ninth Circuit can hear the case with all judges participating. In practice, however, such a hearing has only been asked for four times; the requests have all been denied.
The United States Court of Appeals for the Fifth Circuit, with 17 judges, is eligible to adopt a similar procedure and has done so in 1986. State of La. ex rel. Guste v. M/V TESTBANK , 752 F.2d 1019 (5th Cir. 1985) (en bank).