29 C.F.R. § 18.56 – Subpoena.

(a) In general.
1. (1) Upon written application of a party the judge may issue a subpoena authorized by statute or law that requires a witness to attend and to produce relevant papers, books, documents, or tangible things in the witness' possession or under the witness' control.
2. (2) Form and contents—(i) Requirements—in general. Every subpoena must:
  1. (A) State the title of the matter and show the case number assigned by the Office of Administrative Law Judges or the Office of Worker's Compensation Programs. In the event that the case number is an individual's Social Security number only the last four numbers may be used. See § 18.31(a)(1);
  2. (B) Bear the signature of the issuing judge;
  3. (C) Command each person to whom it is directed to do the following at a specified time and place: attend and testify; produce designated documents, electronically stored information, or tangible things in that person's possession, custody, or control; or permit the inspection of premises; and
  4. (D) Set out the text of paragraphs (c) and (d) of this section.
  5. (ii) Command to attend a deposition—notice of the recording method. A subpoena commanding attendance at a deposition must state the method for recording the testimony.
  6. (iii) Combining or separating a command to produce or to permit inspection; specifying the form for electronically stored information. A command to produce documents, electronically stored information, or tangible things or to permit the inspection of premises may be included in a subpoena commanding attendance at a deposition or hearing, or may be set out in a separate subpoena. A subpoena may specify the form or forms in which electronically stored information is to be produced.
  7. (iv) Command to produce; included obligations. A command in a subpoena to produce documents, electronically stored information, or tangible things requires the responding party to permit inspection, copying, testing, or sampling of the materials.
(b) Service—(1) By whom; tendering fees; serving a copy of certain subpoenas. Any person who is at least 18 years old and not a party may serve a subpoena. Serving a subpoena requires delivering a copy to the named person and, if the subpoena requires that person's attendance, tendering with it the fees for 1 day's attendance and the mileage allowed by law. Service may also be made by certified mail with return receipt. Fees and mileage need not be tendered when the subpoena issues on behalf of the United States or any of its officers or agencies. If the subpoena commands the production of documents, electronically stored information, or tangible things or the inspection of premises before the formal hearing, then before it is served on the person to whom it is directed, a notice and copy of the subpoena must be served on each party.
(2) Service in the United States. Subject to paragraph (c)(3)(i)(B) of this section, a subpoena may be served at any place within a State, Commonwealth, or Territory of the United States, or the District of Columbia.
(3) Service in a foreign country. 28 U.S.C. 1783 governs issuing and serving a subpoena directed to a United States national or resident who is in a foreign country.
(4) Proof of service. Proving service, when necessary, requires filing with the judge a statement showing the date and manner of service and the names of the persons served. The statement must be certified by the server.
(c) Protecting a person subject to a subpoena—(1) Avoiding undue burden; sanctions. A party or representative responsible for requesting, issuing, or serving a subpoena must take reasonable steps to avoid imposing undue burden on a person subject to the subpoena. The judge must enforce this duty and impose an appropriate sanction.
(2) Command to produce materials or permit inspection—(i) Appearance not required. A person commanded to produce documents, electronically stored information, or tangible things, or to permit the inspection of premises, need not appear in person at the place of production or inspection unless also commanded to appear for a deposition or hearing.
(ii) Objections. A person commanded to produce documents or tangible things or to permit inspection may serve on the party or representative designated in the subpoena a written objection to inspecting, copying, testing or sampling any or all of the materials or to inspecting the premises—or to producing electronically stored information in the form or forms requested. The objection must be served before the earlier of the time specified for compliance or 14 days after the subpoena is served. If an objection is made, the following rules apply:
1. (A) At any time, on notice to the commanded person, the serving party may move the judge for an order compelling production or inspection.
2. (B) These acts may be required only as directed in the order, and the order must protect a person who is neither a party nor a party's officer from significant expense resulting from compliance.
3. (3) Quashing or modifying a subpoena—(i) When required. On timely motion, the judge must quash or modify a subpoena that:
  1. (A) Fails to allow a reasonable time to comply;
  2. (B) Requires a person who is neither a party nor a party's officer to travel more than 100 miles from where that person resides, is employed, or regularly transacts business in person—except that, subject to paragraph (c)(3)(ii)(C) of this section, the person may be commanded to attend the formal hearing;
  3. (C) Requires disclosure of privileged or other protected matter, if no exception or waiver applies; or
  4. (D) Subjects a person to undue burden.
  5. (ii) When permitted. To protect a person subject to or otherwise affected by a subpoena, the judge may, on motion, quash or modify the subpoena if it requires:
    1. (A) Disclosing a trade secret or other confidential research, development, or commercial information;
    2. (B) Disclosing an unretained expert's opinion or information that does not describe specific occurrences in dispute and results from the expert's study that was not requested by a party; or
    3. (C) A person who is neither a party nor a party's officer to incur substantial expense to travel more than 100 miles to attend the formal hearing.
  6. (iii) Specifying conditions as an alternative. In the circumstances described in paragraph (c)(3)(ii) of this section, the judge may, instead of quashing or modifying a subpoena, order appearance or production under specified conditions if the serving party:
    1. (A) Shows a substantial need for the testimony or material that cannot be otherwise met without undue hardship; and
    2. (B) Ensures that the subpoenaed person will be reasonably compensated.
    3. (d) Duties in responding to a subpoena—(1) Producing documents or electronically stored information. These procedures apply to producing documents or electronically stored information:
    4. (i) Documents. A person responding to a subpoena to produce documents must produce them as they are kept in the ordinary course of business or must organize and label them to correspond to the categories in the demand.
    5. (ii) Form for producing electronically stored information not specified. If a subpoena does not specify a form for producing electronically stored information, the person responding must produce it in a form or forms in which it is ordinarily maintained or in a reasonably usable form or forms.
    6. (iii) Electronically stored information produced in only one form. The person responding need not produce the same electronically stored information in more than one form.
    7. (iv) Inaccessible electronically stored information. The person responding need not provide discovery of electronically stored information from sources that the person identifies as not reasonably accessible because of undue burden or cost. On motion to compel discovery or for a protective order, the person responding must show that the information is not reasonably accessible because of undue burden or cost. If that showing is made, the judge may nonetheless order discovery from such sources if the requesting party shows good cause, considering the limitations of § 18.51(b)(4)(iii). The judge may specify conditions for the discovery.
    8. (2) Claiming privilege or protection—(i) Information withheld. A person withholding subpoenaed information under a claim that it is privileged or subject to protection as hearing-preparation material must:
      1. (A) Expressly make the claim; and
      2. (B) Describe the nature of the withheld documents, communications, or tangible things in a manner that, without revealing information itself privileged or protected, will enable the parties to assess the claim.
      3. (ii) Information produced. If information produced in response to a subpoena is subject to a claim of privilege or of protection as hearing-preparation material, the person making the claim may notify any party that received the information of the claim and the basis for it. After being notified, a party must promptly return, sequester, or destroy the specified information and any copies it has; must not use or disclose the information until the claim is resolved; must take reasonable steps to retrieve the information if the party disclosed it before being notified; and may promptly present the information to the judge in camera for a determination of the claim. The person who produced the information must preserve the information until the claim is resolved.
      4. (e) Failure to obey. When a person fails to obey a subpoena, the party adversely affected by the failure may, when authorized by statute or by law, apply to the appropriate district court to enforce the subpoena.