5 C.F.R. § 2423.28 – Subpoenas.

(a) When necessary. Where the parties are in agreement that the appearance of witnesses or the production of documents is necessary, and such witnesses agree to appear, no subpoena need be sought.
(b) Requests for subpoenas. A request for a subpoena by any person, as defined in 5 U.S.C. 7103(a)(1), shall be in writing and filed with the Office of Administrative Law Judges not less than 10 days prior to the hearing, or with the Administrative Law Judge during the hearing. Requests for subpoenas made less than 10 days prior to the hearing shall be granted on sufficient explanation of why the request was not timely filed.
(c) Subpoena procedures. The Office of Administrative Law Judges, or any other employee of the Authority designated by the Authority, as appropriate, shall furnish the requester the subpoenas sought, provided the request is timely made. Requests for subpoenas may be made ex parte. Completion of the specific information in the subpoena and the service of the subpoena are the responsibility of the party on whose behalf the subpoena was issued.
(d) Service of subpoena. A subpoena may be served by any person who is at least 18 years old and who is not a party to the proceeding. The person who served the subpoena must certify that he or she did so:
1. (1) By delivering it to the witness in person,
2. (2) By registered or certified mail, or
3. (3) By delivering the subpoena to a responsible person (named in the document certifying the delivery) at the residence or place of business (as appropriate) of the person for whom the subpoena was intended. The subpoena shall show on its face the name and address of the party on whose behalf the subpoena was issued.
(e)
1. (1) Petition to revoke subpoena. Any person served with a subpoena who does not intend to comply shall, within 5 days after the date of service of the subpoena upon such person, petition in writing to revoke the subpoena. A copy of any petition to revoke a subpoena shall be served on the party on whose behalf the subpoena was issued. Such petition to revoke, if made prior to the hearing, and a written statement of service, shall be filed with the Office of Administrative Law Judges for ruling. A petition to revoke a subpoena filed during the hearing, and a written statement of service, shall be filed with the Administrative Law Judge.
2. (2) The Administrative Law Judge, or any other employee of the Authority designated by the Authority, as appropriate, shall revoke the subpoena if the person or evidence, the production of which is required, is not material and relevant to the matters under investigation or in question in the proceedings, or the subpoena does not describe with sufficient particularity the evidence the production of which is required, or if for any other reason sufficient in law the subpoena is invalid. The Administrative Law Judge, or any other employee of the Authority designated by the Authority, as appropriate, shall state the procedural or other ground for the ruling on the petition to revoke. The petition to revoke, any answer thereto, and any ruling thereon shall not become part of the official record except upon the request of the party aggrieved by the ruling.
(f) Failure to comply. Upon the failure of any person to comply with a subpoena issued and upon the request of the party on whose behalf the subpoena was issued, the Solicitor of the Authority shall institute proceedings on behalf of such party in the appropriate district court for the enforcement thereof, unless to do so would be inconsistent with law and the Federal Service Labor-Management Relations Statute.