New York CJA Form 21 Authorization and Voucher for Expert and Other Services is a form used in the US federal criminal justice system to authorize payment for expert services, such as those provided by expert witnesses, interpreters, and other specialist services, for defendants in criminal proceedings. The form is issued by the US Court of Appeals for the Second Circuit. It is used to authorize payment for services provided by experts who are either appointed by the court or retained by counsel. The form is composed of three parts: a voucher, a cover sheet, and a services' authorization form. The voucher is used to document the services provided and the associated costs, while the cover sheet is used to provide identifying information about the defendant and the expert service provider. Finally, the services' authorization form is used to authorize payment for the services provided. The different types of New York CJA Form 21 Authorization and Voucher for Expert and Other Services include the Expert Witness Authorization Form, the Interpreter Authorization Form, and the Other Services Authorization Form.