Subpoenas in U.S. Courts

A subpoena is a court-issued legal instrument that compels a person to take a specific action in connection with a judicial proceeding — typically to appear and testify or to produce documents and physical evidence. Subpoenas operate in both federal and state courts, and failure to comply can result in contempt sanctions. Understanding how subpoenas are issued, served, and challenged is essential to grasping how courts gather the evidence they need to resolve disputes in the civil trial process and the criminal trial process.

Definition and Scope

A subpoena (from the Latin sub poena, meaning "under penalty") is a formal mandate issued under the authority of a court or an officer of the court. Under Federal Rule of Civil Procedure (FRCP) Rule 45, a subpoena may be issued by the clerk of court or by an attorney who is authorized to practice in the issuing court. The parallel criminal counterpart is governed by Federal Rule of Criminal Procedure (FRCrP) Rule 17.

Subpoenas fall into two primary categories:

1. Subpoena ad testificandum — Compels a person to appear and give oral testimony at a deposition, hearing, or trial.
2. Subpoena duces tecum — Compels a person or entity to produce documents, records, electronically stored information (ESI), or tangible objects.

A single subpoena may combine both requirements. Subpoenas can be directed at parties to the litigation or at third parties — non-parties who hold information relevant to the case. The scope of what a subpoena may demand is not unlimited; it is bounded by proportionality principles articulated in FRCP Rule 26(b)(1), which requires that requested information be proportional to the needs of the case.

How It Works

The lifecycle of a subpoena follows a structured sequence from issuance through compliance or challenge.

1. Issuance — In federal civil proceedings, any attorney admitted to practice in the court of issuance may issue and sign a subpoena without prior judicial approval (FRCP Rule 45(a)(3)). In federal criminal matters, the court issues the subpoena on request from the defendant or prosecution (FRCrP Rule 17(a)).

2. Service — A subpoena must be personally served on the named individual. FRCP Rule 45(b)(1) requires that service be made by delivering a copy to the named person, and when the subpoena compels attendance, the serving party must simultaneously tender the fees for one day's attendance and the applicable mileage allowance. As of 2023, the federal witness fee is set at $40 per day (28 U.S.C. § 1821).

3. Geographic limits — Under FRCP Rule 45(c), a subpoena for testimony may only command attendance within 100 miles of where the person resides, works, or regularly transacts business, or within the state if the person is a party or a party's officer.

4. Compliance deadline — The subpoena must allow a reasonable time to comply. Courts have found fewer than 14 days to be presumptively unreasonable absent special circumstances.

5. Objection or motion to quash — The recipient may serve a written objection within 14 days of service (for document production) or file a motion to quash or modify the subpoena under FRCP Rule 45(d)(3). Grounds include undue burden, privilege, confidentiality, or geographic overreach.

6. Enforcement — If the recipient fails to comply without adequate justification, the issuing court may hold the person in contempt under FRCP Rule 45(g). Contempt sanctions can include fines or, in some circumstances, incarceration.

Common Scenarios

Subpoenas appear across a wide range of litigation contexts.

Discovery phase — The most common use occurs during discovery, where subpoenas duces tecum are directed at banks, employers, hospitals, and technology platforms to obtain records that parties cannot access directly. A subpoena to a social media platform to produce account records is now routine in both civil and criminal matters.

Trial testimony — When a witness refuses to appear voluntarily, a subpoena ad testificandum ensures the witness is present. In criminal cases, the Sixth Amendment's Compulsory Process Clause — addressed at Sixth Amendment Trial Rights — affirmatively guarantees defendants the right to compel attendance of witnesses in their favor.

Grand jury proceedings — The grand jury process relies almost entirely on subpoenas to gather documents and testimony before charges are filed. Grand jury subpoenas are issued under the court's investigative authority and carry broader geographic reach than trial subpoenas.

Depositions — Subpoenas are used to compel non-party witnesses to appear at depositions. Unlike party witnesses who can be compelled through discovery rules alone, non-parties require a subpoena before they can be obligated to sit for a deposition.

Regulatory and administrative proceedings — Federal agencies including the Securities and Exchange Commission (SEC) and the Federal Trade Commission (FTC) have independent subpoena power under their enabling statutes, distinct from judicial subpoenas, though related documents can enter court through evidentiary procedures covered under the rules of evidence.

Decision Boundaries

Two structural distinctions govern how subpoenas are evaluated and challenged.

Party vs. non-party burden — Courts apply a more protective standard when a subpoena targets a non-party. FRCP Rule 45(d)(1) places an affirmative duty on the issuing attorney to avoid imposing undue burden or expense on non-parties. Courts routinely quash or modify subpoenas directed at non-parties when the requesting party could obtain equivalent information from a party through standard discovery requests.

Privilege and protection — A subpoena cannot override evidentiary privileges. Documents protected by attorney-client privilege, work-product doctrine, Fifth Amendment protections (see Fifth Amendment Rights at Trial), or recognized confidentiality statutes — such as HIPAA protections for medical records under 45 C.F.R. Part 164 — remain outside the compelled production. The recipient must log withheld privileged materials in a privilege log.

Subpoena duces tecum vs. deposition notice — When directed at a party, a document production obligation can be established through a deposition notice combined with a document request under FRCP Rule 30(b)(2), without requiring a separate subpoena. A subpoena duces tecum is the required mechanism only when the target is a non-party.

Federal vs. state court standards — State subpoena practice largely mirrors federal rules but with variation. California Code of Civil Procedure § 1985 et seq. governs state court subpoenas in California and includes specific consumer and employee record protections that exceed federal minimums. Attorneys and litigants operating in state court must consult the applicable state civil rules rather than assuming FRCP standards apply.

References

• Federal Rules of Civil Procedure, Rule 45 — Subpoena (Cornell LII)
• Federal Rules of Criminal Procedure, Rule 17 — Subpoena (Cornell LII)
• 28 U.S.C. § 1821 — Per Diem and Mileage Generally; Subsistence (House OLRC)
• Federal Rules of Civil Procedure, Rule 26 — Duty to Disclose; General Provisions Governing Discovery (Cornell LII)
• 45 C.F.R. Part 164 — HIPAA Security and Privacy Standards (eCFR)
• U.S. Courts — Federal Rules of Civil Procedure (uscourts.gov)
• U.S. Courts — Federal Rules of Criminal Procedure (uscourts.gov)