45 CFR § 160.520 - Subpoenas for attendance at hearing.
(a) A party wishing to procure the appearance and testimony of any person at the hearing may make a motion requesting the ALJ to issue a subpoena if the appearance and testimony are reasonably necessary for the presentation of a party's case.
(b) A subpoena requiring the attendance of a person in accordance with paragraph (a) of this section may also require the person (whether or not the person is a party) to produce relevant and material evidence at or before the hearing.
(c) When a subpoena is served by a respondent on a particular employee or official or particular office of HHS, the Secretary may comply by designating any knowledgeable HHS representative to appear and testify.
(d) A party seeking a subpoena must file a written motion not less than 30 days before the date fixed for the hearing, unless otherwise allowed by the ALJ for good cause shown. That motion must -
(1) Specify any evidence to be produced;
(2) Designate the witnesses; and
(3) Describe the address and location with sufficient particularity to permit those witnesses to be found.
(e) The subpoena must specify the time and place at which the witness is to appear and any evidence the witness is to produce.
(f) Within 15 days after the written motion requesting issuance of a subpoena is served, any party may file an opposition or other response.
(g) If the motion requesting issuance of a subpoena is granted, the party seeking the subpoena must serve it by delivery to the person named, or by certified mail addressed to that person at the person's last dwelling place or principal place of business.