5 CFR § 1201.37 - Witness fees.
(a) Federal employees. Employees of a Federal agency or corporation testifying in any Board proceeding or making a statement for the record will be in official duty status and will not receive witness fees.
(b) Other witnesses. Other witnesses (whether appearing voluntarily or under subpoena) shall be paid the same fee and mileage allowances which are paid subpoenaed witnesses in the courts of the United States.
(c) Payment of witness fees and travel costs. The party requesting the presence of a witness must pay that witness' fees. Those fees must be paid or offered to the witness at the time the subpoena is served, or, if the witness appears voluntarily, at the time of appearance. A Federal agency or corporation is not required to pay or offer witness fees in advance.
(d) A witness who is denied the witness fees and travel costs required by paragraphs (b) and (c) of this section may file a written request that the judge order the party who requested the presence of the witness to provide such fees and travel costs. The judge will act on such a request promptly and, where warranted, will order the party to comply with the requirements of paragraphs (b) and (c) of this section.
(e) An order obtained under paragraph (d) of this section may be enforced as provided under subpart F of this part.