Certain courts, notably U.S. Courts of Appeals and the U.S. Supreme Court, require attorneys to be specifically admitted to practice before them. To find out if a particular attorney has been admitted, call the court clerk (for directories listing court clerks, see "Court Clerks / Court Houses").
To find out how to get admitted to practice before a court, call the court clerk and/or see if the information might be on the court's Web site. (To get an application to practice before the U.S. Court of Appeals for the Second Circuit, call the Court at 212-872-8603).