En banc or in bank is a term used to refer to the hearing of a case by all the judges of a court. Appellate courts in the United States sometimes grant rehearing en banc to reconsider a decision of a panel of the court, 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. More rarely, an appellate court will order hearing en banc as an initial matter. Very rarely, a trial court may hear a matter en banc if, for example, uniformity of decisions on a recurring matter is important and unusual circumstances prevent appellate review.
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 substantially all of their cases en banc. In the United States Court of Appeals for the Ninth Circuit, the phrase "en banc" is used to refer to 11-judge panels, which constitute less than the full court, but which perform the same function as the full United States Court of Appeals in other circuits.