(D) Expert Employed Only for Trial Preparation. Ordinarily, a party may not, by interrogatories or deposition, discover facts known or opinions held by an expert who has been retained or specially employed by another party in anticipation of litigation or to prepare for trial and who is not expected to be called as a witness at trial. But a party may do so only:
(i) as provided in Rule 35(b); or
(ii) on showing exceptional circumstances under which it is impracticable for the party to obtain facts or opinions on the same subject by other means.
(E) Payment. Unless manifest injustice would result, the court must require that the party seeking discovery:
(i) pay the expert a reasonable fee for time spent in responding to discovery under Rule 26(b)(4)(A) or (D); and
(ii) for discovery under (D), also pay the other party a fair portion of the fees and expenses it reasonably incurred in obtaining the expert's facts and opinions.

(5) Claiming Privilege or Protecting Trial-Preparation Materials.
(A) Information Withheld. When a party withholds information otherwise discoverable by claiming that the information is privileged or subject to protection as trial-preparation material, the party must:
(i) expressly make the claim; and
(ii) describe the nature of the documents, communications, or tangible things not produced or dis-closed一and do so in a manner that, without revealing information itself privileged or protected, will enable other parties to assess the claim.
(B) Information Produced. If information produced in discovery is subject to a claim of privilege or of protection as trial-preparation material, the party 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 court under seal for a determination of the claim. The producing party must preserve the information until the claim is resolved.

(c) Protective Orders.
(1) In General. A party or any person from whom discovery is sought may move for a protective order in the court where the action is pending一or as an alternative on matters relating to a deposition, in the court for the district where the deposition will be taken. The motion must include a certification that the movant has in good faith conferred or attempted to confer with other affected parties in an effort to resolve the dispute without court action. The court may, for good cause, issue an order to protect a party or person from annoyance, embarrassment, oppression, or undue burden or expense, including one or more of the following:
(A) forbidding the disclosure or discovery;
(B) specifying terms, including time and place or the allocation of expenses, for the disclosure or discovery;
(C) prescribing a discovery method other than the one selected by the party seeking discovery;
(D) forbidding inquiry into certain matters, or limiting the scope of disclosure or discovery to certain matters;
(E) designating the persons who may be present while the discovery is conducted;
(F) requiring that a deposition be sealed and opened only on court order;
(G) requiring that a trade secret or other confidential research, development, or commercial information not be revealed or be revealed only in a specified way; and
(H) requiring that the parties simultaneously file specified documents or information in sealed envelopes, to be opened as the court directs.
(2) Ordering Discovery. If a motion for a protective order is wholly or partly denied, the court may, on just terms, order that any party or person provide or permit discovery.
(3) Awarding Expenses. Rule 37(a)(5) applies to the award of expenses.

(d) Timing and Sequence of Discovery.
(1) Timing. A party may not seek discovery from any source before the parties have conferred as required by Rule 26(f), except in a proceeding exempted from initial disclosure under Rule 26(a)(1)(B), or when authorized by these rules, by stipulation, or by court order.
(2) Early Rule 34 Requests.
(A) Time to Deliver. More than 21 days after the summons and complaint are served on a party, a request under Rule 34 may be delivered:
(i) to that party by any other party, and
(ii) by that party to any plaintiff or to any other party that has been served.
(B) When Considered Served. The request is considered to have been served at the first Rule 26(f) conference.
(3) Sequence. Unless the parties stipulate or the court orders otherwise for the parties' and witnesses' convenience and in the interests of justice:
(A) methods of discovery may be used in any sequence; and
(B) discovery by one party does not require any other party to delay its discovery.

(e) Supplementing Disclosures and Responses.
(1) In General. A party who has made a disclosure under Rule 26(a)一or who has responded to an interrogatory, request for production, or request for admission一must supplement or correct its disclosure or response:
(A) in a timely manner if the party learns that in some material respect the disclosure or response is incomplete or incorrect, and if the additional or corrective information has not otherwise been made known to the other parties during the discovery process or in writing; or
(B) as ordered by the court.
(2) Expert Witness. For an expert whose report must be disclosed under Rule 26(a)(2)(B), the party's duty to supplement extends both to information included in the report and to information given during the expert's deposition. Any additions or changes to this information must be disclosed by the time the party's pretrial disclosures under Rule 26(a)(3) are due.

(f) CONFERENCE OF THE PARTIES； PLANNING FOR DISCOVERY.
(1) Conference Timing. Except in a proceeding exempted from initial disclosure under Rule 26(a)(1)(B) or when the court orders otherwise, the parties must confer as soon as prac-ticable一and in any event at least 21 days before a scheduling conference is to be held or a scheduling order is due under Rule 16(b).
(2) Conference Content; Parties' Responsibilities. In conferring, the parties must consider the nature and basis of their claims and defenses and the possibilities for promptly settling or resolving the case; make or arrange for the disclosures required by Rule 26(a)(1); discuss any issues about preserving discoverable information; and develop a proposed discovery plan. The attorneys of record and all unrepresented parties that have appeared in the case are jointly responsible for arranging the conference, for attempting in good faith to agree on the proposed discovery plan, and for submitting to the court within 14 days after the conference a written report outlining the plan. The court may order the parties or attorneys to attend the conference in person.

(3) Discovery Plan. A discovery plan must state the parties' views and proposals on:
(A) what changes should be made in the timing, form, or requirement for disclosures under Rule 26(a), including a statement of when initial disclosures were made or will be made;
(B) the subjects on which discovery may be needed, when discovery should be completed, and whether discovery should be conducted in phases or be limited to or focused on particular issues;
(C) any issues about disclosure, discovery, or preservation of electronically stored information, including the form or forms in which it should be produced;
(D) any issues about claims of privilege or of protection as trial-preparation materials, including一if the parties agree on a procedure to assert these claims after produc-tion一whether to ask the court to include their agreement in an order under Federal Rule of Evidence 502;
(E) what changes should be made in the limitations on discovery imposed under these rules or by local rule, and what other limitations should be imposed; and
(F) any other orders that the court should issue under Rule 26(c) or under Rule 16(b) and (c).

(4) Expedited Schedule. If necessary to comply with its expedited schedule for Rule 16(b) conferences, a court may by local rule:
(A) require the parties' conference to occur less than 21 days before the scheduling conference is held or a scheduling order is due under Rule 16(b); and
(B) require the written report outlining the discovery plan to be filed less than 14 days after the parties' conference, or excuse the parties from submitting a written report and permit them to report orally on their discovery plan at the Rule 16(b) conference.

(g) Signing Disclosures and Discovery Requests, Responses, and Objections.
(1) Signature Required; Effect of Signature. Every disclosure under Rule 26(a)(1) or (a)(3) and every discovery request, response, or objection must be signed by at least one attorney of record in the attorney's own name一or by the party personally, if unrepresented一and must state the signer's address, email address, and telephone number. By signing, an attorney or party certifies that to the best of the person's knowledge, information, and belief formed after a reasonable inquiry:
(A) with respect to a disclosure, it is complete and correct as of the time it is made; and
(B) with respect to a discovery request, response, or objection, it is:
(i) consistent with these rules and warranted by existing law or by a nonfrivolous argument for extending, modifying, or reversing existing law, or for establishing new law;
(ii) not interposed for any improper purpose, such as to harass, cause unnecessary delay, or needlessly increase the cost of litigation; and
(iii) neither unreasonable nor unduly burdensome or expensive, considering the needs of the case, prior discovery in the case, the amount in controversy, and the importance of the issues at stake in the action.

(2) Failure to Sign. Other parties have no duty to act on an unsigned disclosure, request, response, or objection until it is signed, and the court must strike it unless a signature is promptly supplied after the omission is called to the attorney's or party's attention.
(3) Sanction for Improper Certification. If a certification violates this rule without substantial justification, the court, on motion or on its own, must impose an appropriate sanction on the signer, the party on whose behalf the signer was acting, or both. The sanction may include an order to pay the reasonable expenses, including attorney's fees, caused by the violation.
(As amended Dec. 27, 1946, eff. Mar. 19, 1948; Jan. 21, 1963, eff. July 1, 1963; Feb. 28, 1966, eff. July 1, 1966; Mar. 30, 1970, eff. July 1, 1970; Apr. 29, 1980, eff. Aug. 1, 1980; Apr. 28, 1983, eff. Aug. 1, 1983; Mar. 2, 1987, eff. Aug. 1, 1987; Apr. 22, 1993, eff. Dec. 1, 1993; Apr. 17, 2000, eff. Dec. 1, 2000; Apr. 12, 2006, eff. Dec. 1, 2006; Apr. 30, 2007, eff. Dec. 1, 2007; Apr. 28, 2010, eff. Dec. 1, 2010; Apr. 29, 2015, eff. Dec. 1, 2015.)

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.

(b) Notice of the Deposition; Other Formal Requirements.
(1) Notice in General. A party who wants to depose a person by oral questions must give reasonable written notice to every other party. The notice must state the time and place of the deposition and, if known, the deponent's name and address. If the name is unknown, the notice must provide a general description sufficient to identify the person or the particular class or group to which the person belongs.
(2) Producing Documents. If a subpoena duces tecum is to be served on the deponent, the materials designated for production, as set out in the subpoena, must be listed in the notice or in an attachment. The notice to a party deponent may be accompanied by a request under Rule 34 to produce documents and tangible things at the deposition.
(3) Method of Recording.
(A) Method Stated in the Notice. The party who notices the deposition must state in the notice the method for recording the testimony. Unless the court orders otherwise, testimony may be recorded by audio, audiovisual, or stenographic means. The noticing party bears the recording costs. Any party may arrange to transcribe a deposition.
(B) Additional Method. With prior notice to the deponent and other parties, any party may designate another method for recording the testimony in addition to that specified in the original notice. That party bears the expense of the additional record or transcript unless the court orders otherwise.

(4) By Remote Means. The parties may stipulate一or the court may on motion order一that a deposition be taken by telephone or other remote means. For the purpose of this rule and Rules 28(a), 37(a)(2), and 37(b)(1), the deposition takes place where the deponent answers the questions.
(5) Officer's Duties.
(A) Before the Deposition. Unless the parties stipulate otherwise, a deposition must be conducted before an officer appointed or designated under Rule 28. The officer must begin the deposition with an on-the-record statement that includes:
(i) the officer's name and business address;
(ii) the date, time, and place of the deposition;
(iii) the deponent's name;
(iv) the officer's administration of the oath or affirmation to the deponent; and
(v) the identity of all persons present.
(B) Conducting the Deposition; Avoiding Distortion. If the deposition is recorded nonstenographically, the officer must repeat the items in Rule 30(b)(5)(A)(i)-(iii) at the beginning of each unit of the recording medium. The deponent's and attorneys' appearance or demeanor must not be distorted through recording techniques.
(C) After the Deposition. At the end of a deposition, the officer must state on the record that the deposition is complete and must set out any stipulations made by the attorneys about custody of the transcript or recording and of the exhibits, or about any other pertinent matters.

(6) Notice or Subpoena Directed to an Organization. In its notice or subpoena, a party may name as the deponent a public or private corporation, a partnership, an association, a governmental agency, or other entity and must describe with reasonable particularity the matters for examination. The named organization must designate one or more officers, directors, or managing agents, or designate other persons who consent to testify on its behalf; and it may set out the matters on which each person designated will testify. Before or promptly after the notice or subpoena is served, the serving party and the organization must confer in good faith about the matters for examination. A subpoena must advise a nonparty organization of its duty to confer with the serving party and to designate each person who will testify. The persons designated must testify about information known or reasonably available to the organization. This paragraph (6) does not preclude a deposition by any other procedure allowed by these rules.

(c) Examination and Cross-Examination; Record of the Examination; Objections; Written Questions.
(1) Examination and Cross-Examination. The examination and cross-examination of a deponent proceed as they would at trial under the Federal Rules of Evidence, except Rules 103 and 615. After putting the deponent under oath or affirmation, the officer must record the testimony by the method designated under Rule 30(b)(3)(A). The testimony must be recorded by the officer personally or by a person acting in the presence and under the direction of the officer.
(2) Objections. An objection at the time of the examination一 whether to evidence, to a party's conduct, to the officer's qualifications, to the manner of taking the deposition, or to any other aspect of the deposition一must be noted on the record, but the examination still proceeds; the testimony is taken subject to any objection. An objection must be stated concisely in a nonargumentative and nonsuggestive manner. A person may instruct a deponent not to answer only when necessary to preserve a privilege, to enforce a limitation ordered by the court, or to present a motion under Rule 30(d)(3).
(3) Participating Through Written Questions. instead of participating in the oral examination, a party may serve written questions in a sealed envelope on the party noticing the deposition, who must deliver them to the officer. The officer must ask the deponent those questions and record the answers verbatim.

(d) Duration; Sanction; Motion to Terminate or Limit.
(1) Duration. Unless otherwise stipulated or ordered by the court, a deposition is limited to one day of 7 hours. The court must allow additional time consistent with Rule 26(b)(1) and
(2) if needed to fairly examine the deponent or if the deponent, another person, or any other circumstance impedes or delays the examination.
(2) Sanction. The court may impose an appropriate sanction一including the reasonable expenses and attorney's fees incurred by any party一on a person who impedes, delays, or frustrates the fair examination of the deponent.
(3) Motion to Terminate or Limit.
(A) Grounds. At any time during a deposition, the deponent or a party may move to terminate or limit it on the ground that it is being conducted in bad faith or in a manner that unreasonably annoys, embarrasses, or oppresses the deponent or party. The motion may be filed in the court where the action is pending or the deposition is being taken. If the objecting deponent or party so demands, the deposition must be suspended for the time necessary to obtain an order.
(B) Order. The court may order that the deposition be terminated or may limit its scope and manner as provided in Rule 26(c). If terminated, the deposition may be resumed only by order of the court where the action is pending.
(C) Award of Expenses. Rule 37(a)(5) applies to the award of expenses.

(e) Review by the Witness; Changes.
(1) Review; Statement of Changes. On request by the deponent or a party before the deposition is completed, the deponent must be allowed 30 days after being notified by the officer that the transcript or recording is available in which:
(A) to review the transcript or recording; and
(B) if there are changes in form or substance, to sign a statement listing the changes and the reasons for making them.
(2) Changes Indicated in the Officer's Certificate. The officer must note in the certificate prescribed by Rule 30(f)(1) whether a review was requested and, if so, must attach any changes the deponent makes during the 30-day period.

(f) Certification and Delivery; Exhibits; Copies of the Transcript or Recording; Filing.
(1) Certification and Delivery. The officer must certify in writing that the witness was duly sworn and that the deposition accurately records the witness's testimony. The certificate must accompany the record of the deposition. Unless the court orders otherwise, the officer must seal the deposition in an envelope or package bearing the title of the action and marked (‘Deposition of [witness's name]'' and must promptly send it to the attorney who arranged for the transcript or recording. The attorney must store it under conditions that will protect it against loss, destruction, tampering, or deterioration.

(2) Documents and Tangible Things.
(A) Originals and Copies. Documents and tangible things produced for inspection during a deposition must, on a party's request, be marked for identification and attached to the deposition. Any party may inspect and copy them. But if the person who produced them wants to keep the originals, the person may:
(i) offer copies to be marked, attached to the deposition, and then used as originals一after giving all parties a fair opportunity to verify the copies by comparing them with the originals; or
(ii) give all parties a fair opportunity to inspect and copy the originals after they are marked一in which event the originals may be used as if attached to the deposition.
(B) Order Regarding the Originals. Any party may move for an order that the originals be attached to the deposition pending final disposition of the case.

(3) Copies of the Transcript or Recording. Unless otherwise stipulated or ordered by the court, the officer must retain the stenographic notes of a deposition taken stenographically or a copy of the recording of a deposition taken by another method. When paid reasonable charges, the officer must furnish a copy of the transcript or recording to any party or the deponent.
(4) Notice of Filing. A party who files the deposition must promptly notify all other parties of the filing.

(g) Failure to Attend a Deposition or Serve a Subpoena; Expenses. A party who, expecting a deposition to be taken, attends in person or by an attorney may recover reasonable expenses for attending, including attorney's fees, if the noticing party failed to:
(1) attend and proceed with the deposition; or
(2) serve a subpoena on a nonparty deponent, who consequently did not attend.
(As amended Jan. 21, 1963, eff. July 1, 1963; Mar. 30, 1970, eff. July 1, 1970; Mar. 1, 1971, eff. July 1, 1971; Nov. 20, 1972, eff. July 1, 1975; Apr. 29, 1980, eff. Aug. 1, 1980; Mar. 2, 1987, eff. Aug. 1, 1987; Apr. 22, 1993, eff. Dec. 1, 1993; Apr. 17, 2000, eff. Dec. 1, 2000; Apr. 30, 2007, eff. Dec. 1, 2007; Apr. 29, 2015, eff. Dec. 1, 2015; Apr. 27, 2020, eff. Dec. 1, 2020.)