How Evidence and Subpoenas Work in Administrative Hearings

In an administrative hearing, evidence rules are looser than in court and subpoenas come from the agency rather than a clerk. The Administrative Procedure Act lets a presiding judge admit almost any oral or written material that is relevant and reliable, and it directs agencies to issue subpoenas to a party on request when the agency’s governing statute authorizes them.¹² That combination — permissive admission plus agency-issued compulsory process — shapes how evidence and subpoenas in administrative hearings actually work, and it changes what a careful party needs to prepare.

What Counts as Admissible Evidence

The APA tells agencies to exclude evidence that is irrelevant, immaterial, or unduly repetitious, and otherwise leaves admission to the judge.¹ The Federal Rules of Evidence do not apply wholesale. Documents, testimony, agency records, inspection reports, photographs, correspondence, financial records, and sworn declarations can all come in without the foundation a courtroom would demand.

Hearsay is the biggest divergence from trial practice. In an administrative hearing it routinely comes in. The Supreme Court held in Richardson v. Perales that written medical reports from doctors who examined a Social Security disability claimant counted as substantial evidence supporting the agency’s decision, even though the claimant never cross-examined the authors.³

Permissive admission is not the same as persuasive weight. A notarized affidavit from an eyewitness is worth more than a secondhand email summary. Records kept in the ordinary course of business generally get strong deference. You can get more into the record than you could in court, but the quality of what you put there still decides whether the judge is persuaded.

Who Carries the Burden

Unless a specific statute says otherwise, the party proposing an agency action carries the burden of proof — typically the agency in an enforcement case, or the applicant in a benefits claim.¹ The usual standard is preponderance of the evidence: more likely than not.

Which side you stand on changes your strategy. If the agency is trying to revoke a license or impose a fine, the agency has to prove its case, and you may win by poking holes rather than building an affirmative record. If you are applying for benefits, you need to put in enough evidence to establish eligibility.

Privileges and Protected Material

Not everything relevant is fair game. A few categories of information are protected, and knowing when to assert a privilege matters.

Attorney-Client Privilege

Confidential communications with your lawyer about legal advice are protected in administrative hearings as they would be in court. The privilege covers what you told your attorney and the advice received back. Sharing that advice outside the legal relationship can waive it. Federal agencies can assert the privilege for communications with their own counsel; limited sharing among agency employees working on the same matter does not waive it.

Trade Secrets and Confidential Business Information

If a hearing involves sensitive commercial data, either party can ask the presiding judge for a protective order setting out how the material must be marked, who can see it, and how it must be handled. In some agencies, outside counsel may review it while in-house counsel is barred to prevent competitive misuse. If you are served with a subpoena seeking trade secrets, requesting a protective order is the mechanism that keeps that information out of the public record.

The Fifth Amendment

The privilege against self-incrimination applies in administrative proceedings. You can refuse to answer questions if a truthful answer would expose you to criminal liability. The cost is different from a criminal trial: here the judge may draw an adverse inference from your silence. That inference alone cannot be the sole basis for a finding against you, but combined with other evidence it can decide the case. If you intend to invoke the privilege, make sure your case does not need your testimony to survive.

Expert Witnesses and Disclosure

Technical disputes — chemical exposure levels, risk-model compliance, whether a medical condition meets a statutory definition — often turn on expert testimony. Agencies generally expect advance notice of who your expert is and what they will say.

Many agencies follow a framework similar to the federal courts’ approach under Rule 26: identity, qualifications, the opinions the expert will offer, and the basis for those opinions.⁴ A retained expert typically must provide a written report covering every opinion they will express, the facts and data relied on, their qualifications, and their compensation. An employee or treating physician with relevant expertise may only need to disclose the subject matter and a summary of expected opinions.

Disclosure deadlines fall well before the hearing. Missing one can mean exclusion, which in a technical case is often fatal. Work backward from the scheduling order so your expert has time to review the record and prepare the report before the disclosure date.

How to Request a Subpoena

When testimony or documents are needed from someone who will not cooperate voluntarily, a subpoena compels participation. The APA directs agencies to issue subpoenas to a party upon request when authorized by the agency’s governing statute.² Most agencies ask you to show the evidence is generally relevant and the request reasonable in scope.

There are two kinds. A standard subpoena compels a person to appear and testify. A subpoena duces tecum compels the production of documents, records, or other tangible items. If you need both from the same person, specify both.

Some agencies, like the National Labor Relations Board, provide standardized forms.⁵ Across agencies, a workable request includes:

Full name and address of the witness. Aliases or incomplete addresses cause problems.
The case docket number and proceeding title.
A specific description of the documents sought. “All records relating to the claimant” is the kind of request judges reject. “Payroll records for January through June 2025” is the kind they approve.
A statement of relevance tying the material to a claim or defense. The more specific this is, the less likely the judge is to narrow the request.
The hearing date and location where the witness must appear or documents must be produced.

Serving the Subpoena and Paying Witness Fees

Once the judge signs the subpoena, you — the requesting party — are responsible for getting it to the recipient. An improperly served subpoena is unenforceable, and the problem usually surfaces too late to fix.

Most agencies permit personal delivery or certified mail with return receipt requested. Personal delivery produces the strongest proof. Certified mail creates a paper trail through the postal service. Federal Rule 45, which many agencies look to for guidance, calls for delivering a copy to the named person in hand along with the attendance fee.⁶ Email is generally not authorized for service of the subpoena itself, even when parties agree to exchange documents electronically later.

Federal law sets the witness attendance fee at $40 per day plus a mileage allowance equal to the GSA rate for privately owned vehicles, currently $0.725 per mile.⁷⁸ The fee must be tendered at the time of service, not later. Forgetting it gives the recipient a basis to challenge the subpoena. A professional process server typically adds $40 to $145 depending on location.

Enforcing a Subpoena

If a properly served recipient ignores the subpoena, the agency can petition a federal district court to compel compliance. The court will order the witness to appear or produce the records, and refusal at that stage can result in contempt.² To get enforcement you need to show the subpoena was issued under proper authority and served correctly, which means keeping copies of every filing, the signed subpoena, and proof of delivery. Some agencies route enforcement through their general counsel’s office rather than letting the party petition the court directly.

Challenging a Subpoena You Received

If a subpoena served on you is improper, you can fight it, but the window is short. At the NLRB, a petition to revoke must be filed in writing within five business days of receiving the subpoena.⁹ The EEOC follows a similar five-day deadline for subpoenas issued under Title VII, the ADA, and GINA; there is no comparable revocation mechanism for subpoenas issued under the Age Discrimination in Employment Act or the Equal Pay Act.¹⁰

Where you file depends on timing. Before the hearing starts, the petition typically goes to the regional director or the agency office that issued the subpoena. Once the hearing is underway, it goes to the presiding judge. Either way, serve a copy on the party that requested the subpoena.⁹

Grounds for quashing or narrowing a subpoena generally fall into a few categories:

Unreasonable time to comply.
Privileged or protected material, including attorney-client communications and work product.
Undue burden, where compliance would be disproportionately expensive or disruptive relative to the value of the information.
Trade secrets or confidential commercial information that could cause competitive harm if disclosed without protection.

If the judge denies your petition, comply. Ignoring the subpoena after losing invites the enforcement proceedings described above.

Presenting Evidence at the Hearing

How you organize the presentation matters as much as what you brought.

Introducing Exhibits

Each document or item enters the record through a formal identification process. You mark it with a label — Petitioner Exhibit 1, Agency Exhibit A, or whatever the agency uses — and provide copies to the other side and the judge. A witness typically authenticates it by explaining where it came from and confirming its accuracy. The judge then rules on admission. If you forget to formally move an exhibit into evidence before the hearing closes, it stays marked for identification only and never becomes part of the decision record. This happens more often than it should.

Witness Testimony

You have the right to present oral and documentary evidence, submit rebuttal evidence, and conduct cross-examination as needed to develop the facts.¹ Direct examination draws out the witness’s knowledge through open-ended questions. Cross-examination follows to test credibility or expose inconsistencies. The judge may also ask questions to fill gaps. Everything is transcribed or recorded.

In some proceedings, particularly benefits and licensing matters, the agency may allow some or all of the evidence to come in on paper rather than through live testimony, provided no party is prejudiced.¹ A written submission saves travel and time; it also forfeits the persuasive weight of a live witness and any chance to cross-examine on the spot.

Preserving the Record

The transcript, the admitted exhibits, and all papers filed in the proceeding together form the exclusive record on which the judge decides.¹ On appeal to federal court, that same record is what the reviewing judge sees. There is no second chance to add evidence you forgot or chose to withhold.

Objections

When the other side offers evidence you believe should be excluded, object on the record and state your grounds concisely. The judge must rule, and both the objection and the ruling must appear in the record.¹¹ Failing to object at the time waives the issue on appeal. Make the objection even when you expect it to be overruled, because preserving it is the only way to raise the point later.

Offers of Proof

The reverse applies when the judge excludes your evidence. Describe what the evidence would have shown, explain its purpose, and state why it should be admitted. This gives the judge a chance to reconsider and creates a record a reviewing court can evaluate. Without an offer of proof, an appellate court has no basis to assess the exclusion, and the error is effectively waived.

What Review Looks Like

For formal hearings under APA sections 556 and 557, a federal court on review asks whether substantial evidence in the record as a whole supports the agency’s conclusion. The court can also set aside agency action that is arbitrary, that violates constitutional rights, that exceeds statutory authority, or that was reached without required procedures.¹² Because review is confined to the record, every missed exhibit, unobjected error, and absent offer of proof becomes a gap that works against you.

When the Other Side Refuses to Cooperate

If a party refuses to produce requested documents or declines to testify, the judge has discretion to draw an adverse inference — essentially treating the missing evidence as unfavorable to the party who withheld it. The inference is not automatic. The judge weighs who carries the burden of proof, the severity of the potential penalty, and how much independent evidence already exists.

An adverse inference cannot stand alone. If the only evidence of wrongdoing is a party’s silence, the judge should not draw the inference. Where other evidence points in the same direction, though, the refusal can tip the outcome. If you intend to invoke a privilege, build the rest of your case so it does not depend on filling that gap yourself.

1
Office of the Law Revision Counsel. 5 USC 556
2
Office of the Law Revision Counsel. 5 USC 555 – Ancillary Matters
3
Justia U.S. Supreme Court Center. Richardson v. Perales, 402 U.S. 389 (1971)
4
Legal Information Institute. Federal Rules of Civil Procedure Rule 26
5
National Labor Relations Board. Fillable Forms
6
Legal Information Institute. Federal Rules of Civil Procedure Rule 45 – Subpoena
7
Office of the Law Revision Counsel. 28 USC 1821
8
U.S. General Services Administration. Privately Owned Vehicle (POV) Mileage Reimbursement Rates
9
eCFR. 29 CFR 102.31
10
U.S. Equal Employment Opportunity Commission. EEOC Office of General Counsel Litigation Services to the Public
11
eCFR. 43 CFR 4.1046
12
Office of the Law Revision Counsel. 5 USC 706 – Scope of Review