Rule 27. Depositions to Perpetuate Testimony
(a) Before an Action Is Filed.
(1) Petition. A person who wants to perpetuate testimony about any matter cognizable in a United States court may file a verified petition in the district court for the district where any expected adverse party resides. The petition must ask for an order authorizing the petitioner to depose the named persons in order to perpetuate their testimony. The petition must be titled in the petitioner's name and must show:
(A) that the petitioner expects to be a party to an action cognizable in a United States court but cannot presently bring it or cause it to be brought;
(B) the subject matter of the expected action and the petitioner's interest;
(C) the facts that the petitioner wants to establish by the proposed testimony and the reasons to perpetuate it;
(D) the names or a description of the persons whom the petitioner expects to be adverse parties and their addresses, so far as known; and
(E) the name, address, and expected substance of the testimony of each deponent.

(2) Notice and Service. At least 21 days before the hearing date, the petitioner must serve each expected adverse party with a copy of the petition and a notice stating the time and place of the hearing. The notice may be served either inside or outside the district or state in the manner provided in Rule 4. If that service cannot be made with reasonable diligence on an expected adverse party, the court may order service by publication or otherwise. The court must appoint an attorney to represent persons not served in the manner provided in Rule 4 and to cross-examine the deponent if an unserved person is not otherwise represented. If any expected adverse party is a minor or is incompetent, Rule 17(c) applies.
(3) Order and Examination. If satisfied that perpetuating the testimony may prevent a failure or delay of justice, the court must issue an order that designates or describes the persons whose depositions may be taken, specifies the subject matter of the examinations, and states whether the depositions will be taken orally or by written interrogatories. The depositions may then be taken under these rules, and the court may issue orders like those authorized by Rules 34 and 35. A reference in these rules to the court where an action is pending means, for purposes of this rule, the court where the petition for the deposition was filed.
(4) Using the Deposition. A deposition to perpetuate testimony may be used under Rule 32(a) in any later-filed districtcourt action involving the same subject matter if the deposition either was taken under these rules or, although not so taken, would be admissible in evidence in the courts of the state where it was taken.

(b) Pending Appeal.
(1) In General. The court where a judgment has been rendered may, if an appeal has been taken or may still be taken, permit a party to depose witnesses to perpetuate their testimony for use in the event of further proceedings in that court.
(2) Motion. The party who wants to perpetuate testimony may move for leave to take the depositions, on the same notice and service as if the action were pending in the district court. The motion must show:
(A) the name, address, and expected substance of the testimony of each deponent; and
(B) the reasons for perpetuating the testimony.
(3) Court Order. If the court finds that perpetuating the testimony may prevent a failure or delay of justice, the court may permit the depositions to be taken and may issue orders like those authorized by Rules 34 and 35. The depositions may be taken and used as any other deposition taken in a pending district-court action.

(c) Perpetuation by an Action. This rule does not limit a court's power to entertain an action to perpetuate testimony.
(As amended Dec. 27, 1946, eff. Mar. 19, 1948; Dec. 29, 1948, eff. Oct. 20, 1949; Mar. 1, 1971, eff. July 1, 1971; Mar. 2, 1987, eff. Aug. 1, 1987; Apr. 25, 2005, eff. Dec. 1, 2005; Apr. 30, 2007, eff. Dec. 1, 2007; Mar. 26, 2009, eff. Dec. 1, 2009.)

Rule 28. Persons Before Whom Depositions May Be Taken
(a) Within the United States.
(1) In General. Within the United States or a territory or insular possession subject to United States jurisdiction, a deposition must be taken before:
(A) an officer authorized to administer oaths either by federal law or by the law in the place of examination; or
(B) a person appointed by the court where the action is pending to administer oaths and take testimony.
(2) Definition of "Officer." The term ‘‘officer'' in Rules 30, 31, and 32 includes a person appointed by the court under this rule or designated by the parties under Rule 29(a).

(b) In a Foreign Country.
(1) In General. A deposition may be taken in a foreign country:
(A) under an applicable treaty or convention;
(B) under a letter of request, whether or not captioned a ‘‘letter rogatory'';
(C) on notice, before a person authorized to administer oaths either by federal law or by the law in the place of examination; or
(D) before a person commissioned by the court to administer any necessary oath and take testimony.

(2) Issuing a Letter of Request or a Commission. A letter of request, a commission, or both may be issued:
(A) on appropriate terms after an application and notice of it; and
(B) without a showing that taking the deposition in another manner is impracticable or inconvenient.
(3) Form of a Request, Notice, or Commission. When a letter of request or any other device is used according to a treaty or convention, it must be captioned in the form prescribed by that treaty or convention. A letter of request may be addressed ‘‘To the Appropriate Authority in [name of country].'' A deposition notice or a commission must designate by name or descriptive title the person before whom the deposition is to be taken.
(4) Letter of Request一Admitting Evidence. Evidence obtained in response to a letter of request need not be excluded merely because it is not a verbatim transcript, because the testimony was not taken under oath, or because of any similar departure from the requirements for depositions taken within the United States.

(c) Disqualification. A deposition must not be taken before a person who is any party's relative, employee, or attorney; who is related to or employed by any party's attorney; or who is financially interested in the action.
(As amended Dec. 27, 1946, eff. Mar. 19, 1948; Jan. 21, 1963, eff. July 1, 1963; Apr. 29, 1980, eff. Aug. 1, 1980; Mar. 2, 1987, eff. Aug. 1, 1987; Apr. 22, 1993, eff. Dec. 1, 1993; Apr. 1, 2007, eff. Dec. 1, 2007.)

Rule 29. Stipulations About Discovery Procedure
Unless the court orders otherwise, the parties may stipulate that:
(a) a deposition may be taken before any person, at any time or place, on any notice, and in the manner specified一in which event it may be used in the same way as any other deposition; and
(b) other procedures governing or limiting discovery be modi-fied一but a stipulation extending the time for any form of discovery must have court approval if it would interfere with the time set for completing discovery, for hearing a motion, or for trial.
(As amended Mar. 30, 1970, eff. July 1, 1970; Apr. 22, 1993, eff. Dec. 1, 1993; Apr. 30, 2007, eff. Dec. 1, 2007.)

Rule 30. Depositions by Oral Examination
(a) When a Deposition May Be Taken.
(1) Without Leave. A party may, by oral questions, depose any person, including a party, without leave of court except as provided in Rule 30(a)(2). The deponent's attendance may be compelled by subpoena under Rule 45.
(2) With Leave. A party must obtain leave of court, and the court must grant leave to the extent consistent with Rule 26(b)(1) and (2):
(A) if the parties have not stipulated to the deposition and:
(i) the deposition would result in more than 10 depositions being taken under this rule or Rule 31 by the plaintiffs, or by the defendants, or by the third-party defendants;
(ii) the deponent has already been deposed in the case; or
(iii) the party seeks to take the deposition before the time specified in Rule 26(d), unless the party certifies in the notice, with supporting facts, that the deponent is expected to leave the United States and be unavailable for examination in this country after that time; or
(B) if the deponent is confined in prison.