45 CFR § 1149.38 - Can witnesses be subpoenaed?
(a) A party wishing to procure the appearance and testimony of any individual at the hearing may request that the ALJ issue a subpoena.
(b) A subpoena requiring the attendance and testimony of an individual may also require the individual to produce documents at the hearing.
(c) A party seeking a subpoena must file a written request not less than 15 days before the date of the hearing unless otherwise allowed by the ALJ upon a showing of good cause. Such request must specify any documents to be produced, must designate the witnesses, and describe the address and location of the desired witness with sufficient particularity to permit such witnesses to be found.
(d) The subpoena must specify the time and place at which the witness is to appear and any documents the witness is to produce.
(e) The party seeking the subpoena must serve it in the manner prescribed in § 1149.11. A subpoena on a party or upon an individual under the control of a party may be served by first class mail.