Perjury: Definition, Penalties, and Legal Implications

By Elizabeth Franklin-Best, Esq., and Christopher Zoukis, JD, MBA

Most people who search for “perjury” have not been charged with perjury. They have said something false, or something that was read as false, in a federal setting — a grand jury room, an FBI interview, a sworn declaration, a proffer session, their own trial testimony — and they want to know what happens now. The honest answer is that federal law has three separate false-statement statutes, they have different elements and different maximums, and the one that applies to you depends almost entirely on whether you were under oath and who was listening.

The second honest answer is that a separate perjury prosecution is uncommon. In fiscal year 2025, out of 66,130 federal sentencings with complete guideline information, 15 were sentenced under the perjury guideline. In the same data set, the obstruction-of-justice adjustment was applied 1,598 times — as a two-level increase inside somebody else’s sentencing, not as a case of its own (U.S. Sentencing Commission, Use of Guidelines and Specific Offense Characteristics, FY2025, at p. 117; Chapter Three Adjustments, FY2025, at p. 2). That ratio is the practical heart of this page. The realistic risk for most readers is not a new indictment. It is a heavier sentence in the case they already have.

The three federal statutes, side by side

This is the comparison no dictionary entry gives you, and it is the first thing a federal defense lawyer works out. Every value below is from the current statutory text.

	18 U.S.C. § 1621 — perjury generally	18 U.S.C. § 1623 — false declarations before a grand jury or court	18 U.S.C. § 1001 — false statements
Oath required?	Yes — an oath before a competent tribunal, officer or person, in a case where U.S. law authorizes one; or an unsworn declaration made “under penalty of perjury” under 28 U.S.C. § 1746	Yes — under oath, or a § 1746 declaration	No. The statute contains no oath requirement at all
Forum	Any proceeding where a federal law authorizes an oath — trial, deposition, administrative hearing, sworn written filing	Only “any proceeding before or ancillary to any court or grand jury of the United States”	Any matter within the jurisdiction of the executive, legislative or judicial branch — an FBI or agency interview, a form, an application
Mental state and act	“Willfully and contrary to such oath states or subscribes any material matter which he does not believe to be true”	“Knowingly makes any false material declaration,” or makes or uses information known to contain one	“Knowingly and willfully” falsifies or conceals a material fact by trick, scheme or device; or makes a materially false statement; or uses a false writing
Two-witness rule?	Yes. Falsity cannot rest on one uncorroborated witness — Weiler v. United States, 323 U.S. 606 (1945)	No. § 1623(e): proof beyond a reasonable doubt suffices and “need not be made by any particular number of witnesses”	No. The rule is a perjury doctrine and does not apply
Recantation provision?	None in the statute	Yes — § 1623(d), and it is narrow. See below	None
Statutory maximum	5 years, a fine, or both	5 years — or 10 years if the proceeding was before or ancillary to the Foreign Intelligence Surveillance Court or the FISA Court of Review	5 years — or 8 years if the offense involves international or domestic terrorism, or if the matter relates to an offense under chapter 109A, 109B, 110 or 117, or § 1591
Offense class	Class D felony (18 U.S.C. § 3559(a)(4))	Class D felony at the 5-year max; Class C at the 10-year FISC max	Class D felony
Sentencing guideline	USSG §2J1.3, base offense level 14	USSG §2J1.3, base offense level 14	Ordinarily the fraud guideline, USSG §2B1.1, driven by loss and other characteristics
How it actually turns up	Rarely charged alone; usually a written sworn filing or a civil deposition tied to a federal case	The grand jury statute. This is what a witness who testifies before a federal grand jury is exposed to	The one most readers are actually facing. An unsworn interview with a federal agent, or a form signed for an agency
Public text	law.cornell.edu/uscode/text/18/1621	law.cornell.edu/uscode/text/18/1623	law.cornell.edu/uscode/text/18/1001

A fourth statute sits alongside these: 18 U.S.C. § 1622, subornation of perjury — “Whoever procures another to commit any perjury” — carrying the same five-year maximum. It is the statute for persuading someone else to lie under oath.

The single most useful thing on that table for most people is the § 1001 column. If you spoke to an FBI agent, an IRS special agent, an OIG investigator, a postal inspector or an HHS agent, you were almost certainly not under oath. Federal agents do not administer oaths in interviews. That means § 1621 and § 1623 are the wrong statutes to be reading, and the two-witness rule and the recantation provision — the two features that make perjury genuinely hard for the government — are not available to you. Section 1001 has neither.

Section 1001 has one narrow carve-out worth knowing. Subsection (b) says the statute “does not apply to a party to a judicial proceeding, or that party’s counsel, for statements, representations, writings or documents submitted by such party or counsel to a judge or magistrate in that proceeding.” That protects litigation advocacy. It does not protect anything said to an investigator.

What § 1621 actually requires, element by element

Perjury under § 1621 is not “lying in court.” It is a four-part offense, and the government must prove every part beyond a reasonable doubt. The statute reaches a person who, “having taken an oath before a competent tribunal, officer, or person, in any case in which a law of the United States authorizes an oath to be administered, that he will testify, declare, depose, or certify truly … willfully and contrary to such oath states or subscribes any material matter which he does not believe to be true.”

Unpacked, that is:

1. An oath, in a proceeding where federal law authorizes one. No oath, no § 1621. The statute also reaches unsworn declarations signed “under penalty of perjury” under 28 U.S.C. § 1746 — the line at the bottom of a federal declaration or a federal tax form.
2. A statement that is false. Not incomplete. Not evasive. False.
3. Willfulness — the speaker did not believe it was true. The Supreme Court, defining perjury for sentencing purposes, put it this way: a witness violates § 1621 by giving “false testimony concerning a material matter with the willful intent to provide false testimony, rather than as a result of confusion, mistake, or faulty memory” (United States v. Dunnigan, 507 U.S. 87 (1993)). Getting a date wrong is not perjury. Forgetting is not perjury.
4. Materiality. The false statement has to matter to the proceeding.

Section 1621 also applies extraterritorially — the statute says it applies “whether the statement or subscription is made within or without the United States.”

Section 1623 is deliberately easier for the government, and that is why prosecutors use it. It drops the two-witness rule. It lets the government charge two irreconcilably contradictory sworn statements without alleging which one was the lie, so long as each was material and each was within the limitations period (§ 1623(c)) — with a defense if the defendant believed each declaration was true when he made it. And it defines falsity for conviction as proof “that the defendant while under oath made irreconcilably contradictory declarations material to the point in question.” What it gives back is recantation.

The literal-truth rule: Bronston v. United States

This is the doctrine that separates a defense lawyer from an encyclopedia, and it is the reason the “did you lie?” question is the wrong question.

In Bronston v. United States, 409 U.S. 352 (1973), the Supreme Court held that the federal perjury statute does not reach an answer that is literally true but unresponsive to the question asked and misleading by negative implication — even where the witness meant to mislead. The Court was explicit that intent to evade does not close the gap: “It may well be that petitioner’s answers were not guileless but were shrewdly calculated to evade. Nevertheless, we are constrained to agree … that any special problems arising from the literally true but unresponsive answer are to be remedied through the ‘questioner’s acuity’ and not by a federal perjury prosecution.”

The line worth memorizing is short: “The burden is on the questioner to pin the witness down to the specific object of the questioner’s inquiry.” And the Court’s instruction to prosecutors was blunt: “Precise questioning is imperative as a predicate for the offense of perjury.”

The Court also foreclosed the argument that a jury can infer perjury from a witness’s apparent purpose: “A jury should not be permitted to engage in conjecture whether an unresponsive answer, true and complete on its face, was intended to mislead or divert the examiner; the state of mind of the witness is relevant only to the extent that it bears on whether ‘he does not believe [his answer] to be true.'”

What Bronston means in practice is that the first thing a lawyer does with a threatened perjury charge is get the transcript and read the question, word for word, alongside the answer. A sloppy question and a technically accurate answer is not a perjury case, however unhelpful the answer was.

What Bronston does not do is equally important, and pages that treat it as a general license get it wrong:

• It construes § 1621 and it concerns answers that are literally true. It says nothing about a statement that is simply false.
• It does not apply to 18 U.S.C. § 1001, which is a different statute with different elements and no oath requirement.
• It does not stop a sentencing judge from applying the obstruction adjustment discussed below.
• It is not advice about how to answer questions under oath. Nobody should read a Supreme Court case and try to thread it live in a grand jury room. The place to work out how to answer is with counsel, before you testify.

Materiality, and who decides it

Materiality is an element of all three statutes, and it is decided by the jury, not the judge. In United States v. Gaudin, 515 U.S. 506 (1995), the Supreme Court held that because the Fifth and Sixth Amendments require a jury determination of every element, a defendant charged under § 1001 “had a right to have the jury decide materiality.”

The definition the parties agreed on in Gaudin, drawn from earlier precedent, is the one still used: a statement is material if it has “a natural tendency to influence, or [is] capable of influencing, the decision of the decisionmaking body to which it was addressed.”

Two consequences follow, and they cut in opposite directions. Materiality does not require that anyone was actually fooled, or that the outcome changed — capability of influencing is enough. But it also is not satisfied by any falsehood at all: a lie about something the tribunal was not deciding is not material. Attacking materiality is one of the few defenses that can dispose of a false-statement count without disputing what was said.

The Sentencing Guidelines use their own, near-identical formulation for the obstruction adjustment: “material” means “evidence, fact, statement, or information that, if believed, would tend to influence or affect the issue under determination” (USSG §3C1.1, comment. (n.6)).

What actually happens: the obstruction adjustment, not a new indictment

Here is the sequence that catches people, and no dictionary entry describes it. A defendant testifies at his own trial, or denies conduct in a proffer, or gives the probation officer a version of events the court does not accept. He is convicted. No perjury count is ever filed. At sentencing, the government asks for a two-level increase under USSG §3C1.1 for obstructing the administration of justice, and the judge decides it — on the record before the court, in that same case, weeks later.

The text of the adjustment is short: if the defendant “willfully obstructed or impeded, or attempted to obstruct or impede, the administration of justice with respect to the investigation, prosecution, or sentencing of the instant offense of conviction,” and the conduct related to the offense of conviction and relevant conduct or to a closely related offense, “increase the offense level by 2 levels.”

Dunnigan is the case that governs. It holds three things a reader should know:

• A defendant’s right to testify “does not include a right to commit perjury.”
• The enhancement is not automatic on conviction. “If a defendant objects to a sentence enhancement resulting from her trial testimony, a district court must review the evidence and make independent findings necessary to establish a willful impediment to, or obstruction of, justice, or an attempt to do the same, under the perjury definition we have set out.” Separate findings on each element are “preferable”; a global finding is sufficient only if it “encompasses all of the factual predicates for a finding of perjury.”
• Once those findings are made, the increase follows. “Upon a proper determination that the accused has committed perjury at trial, an enhancement of sentence is required by the Sentencing Guidelines.”

The Guidelines commentary draws the boundary that matters most to anyone who fought their case and lost. Application Note 2 to §3C1.1: “This provision is not intended to punish a defendant for the exercise of a constitutional right. A defendant’s denial of guilt (other than a denial of guilt under oath that constitutes perjury), refusal to admit guilt or provide information to a probation officer, or refusal to enter a plea of guilty is not a basis for application of this provision.” The same note tells courts to be “cognizant that inaccurate testimony or statements sometimes may result from confusion, mistake, or faulty memory.”

Testifying and being disbelieved is not obstruction. Pleading not guilty is not obstruction. Perjury is.

The commentary also lists what does and does not count, and the two lists are the most useful thing on the page for someone who talked to an agent:

• Covered (Application Note 4): committing or suborning perjury; producing a false or altered document during an investigation or judicial proceeding; destroying or concealing material evidence on learning an investigation has begun; providing materially false information to a judge; providing materially false information to a probation officer for a presentence investigation; and “providing a materially false statement to a law enforcement officer that significantly obstructed or impeded the official investigation or prosecution of the instant offense.”
• Ordinarily not covered (Application Note 5): giving a false name at arrest, unless it significantly hindered the case; “making false statements, not under oath, to law enforcement officers, unless Application Note 4(G) above applies”; giving incomplete or misleading information short of a material falsehood to the presentence investigation; and avoiding or fleeing arrest.

Read those two together and the standard for a false statement to an agent becomes clear: it has to have significantly obstructed the investigation, not merely have been untrue.

The other half of the cost — acceptance of responsibility

The two levels are only part of the arithmetic, and this is the part clients are most often surprised by. Application Note 4 to USSG §3E1.1 says: “Conduct resulting in an enhancement under §3C1.1 … ordinarily indicates that the defendant has not accepted responsibility for his criminal conduct. There may, however, be extraordinary cases in which adjustments under both §§3C1.1 and 3E1.1 may apply.”

Acceptance of responsibility is worth two levels, and a third where the offense level before the reduction is 16 or greater and the government moves for it. So a finding of obstruction can move the offense level by four or five in total — up two, and losing two or three that would otherwise have come off. Where the calculation lands after that is entirely the court’s, and no page can tell you what a given judge will do.

A separate rule prevents double counting when perjury is charged. Application Note 7 to §3C1.1 provides that if the defendant is convicted of an offense covered by §2J1.3 (perjury or subornation of perjury), §2J1.2 (obstruction), §2X3.1 (accessory after the fact) or §2X4.1 (misprision), the obstruction adjustment “is not to be applied to the offense level for that offense” unless a significant further obstruction occurred during the prosecution of the obstruction offense itself.

If perjury is charged: how the guideline works

USSG §2J1.3 sets a base offense level of 14 for perjury, subornation of perjury and witness bribery. Two specific offense characteristics can raise it: +8 levels if the offense involved causing or threatening physical injury to a person, or property damage, in order to suborn perjury; and +3 levels if the perjury “resulted in substantial interference with the administration of justice.”

That last phrase is defined, and the definition is broad: it “includes a premature or improper termination of a felony investigation; an indictment, verdict, or any judicial determination based upon perjury, false testimony, or other false evidence; or the unnecessary expenditure of substantial governmental or court resources.”

There is also a cross reference that can take the calculation somewhere much worse. If the perjury was “in respect to a criminal offense,” the court applies USSG §2X3.1 (accessory after the fact) with respect to that offense if it produces a higher offense level. Lying to protect someone in a serious case is therefore sentenced off their offense, not off the flat 14.

Finally, a special instruction: counts of perjury arising from testimony in separate proceedings are not grouped together under §3D1.2. “Separate proceedings” includes a grand jury proceeding and a trial, or a trial and a retrial, or separate trials of co-defendants — but not multiple grand jury sessions in the same case. Repeating the same false account in two forums is not one offense for guideline purposes.

The Guidelines are advisory, but the court must still calculate the range correctly and take it into account before weighing the other sentencing factors. The order of operations lives at USSG §1B1.1, and how a judge moves from a range to a sentence is covered on our federal sentencing basics page.

Recantation under § 1623(d) — the one statutory off-ramp

Section 1623 contains something neither § 1621 nor § 1001 has: a statutory bar to prosecution if the witness takes it back in time. The provision reads:

“Where, in the same continuous court or grand jury proceeding in which a declaration is made, the person making the declaration admits such declaration to be false, such admission shall bar prosecution under this section if, at the time the admission is made, the declaration has not substantially affected the proceeding, or it has not become manifest that such falsity has been or will be exposed.”

Three conditions gate it, and each is a real limit:

1. The same continuous proceeding. Not a letter the following month. Not a correction at the next appearance.
2. The declaration has not substantially affected the proceeding — or,
3. It has not become manifest that the falsity has been or will be exposed. Recanting after being shown the document that contradicts you is the paradigm case of a recantation that comes too late.

The provision bars prosecution under § 1623 only. It is not a defense to § 1621, and it is not a defense to § 1001. And whether the conditions are met in a given case is for the court, not the witness. Nobody should treat § 1623(d) as a plan.

How a false statement is proved, and what the two-witness rule really means

For § 1621, the government cannot prove falsity on one witness’s say-so. The rule, reaffirmed in Weiler, is that “the uncorroborated oath of one witness is not enough to establish the falsity of the testimony of the accused set forth in the indictment”; the falsity must be established “by the testimony of two independent witnesses or one witness and corroborating circumstances.”

Weiler also holds that where a defendant requests it, the judge must instruct the jury on the rule, and that the trustworthiness of corroborating evidence is “a function which belongs exclusively to the jury.” Two things must be shown for corroboration to be sufficient: that the evidence, if true, substantiates the single witness’s testimony, and that the corroborative evidence is trustworthy.

Because the rule exists, § 1621 cases are usually built on documents rather than testimony — a transcript against a bank record, a sworn declaration against an email. And because § 1623(e) abolishes the rule for grand jury and court declarations, and § 1001 never had it, the practical effect of the two-witness rule is much narrower than its reputation.

The evidence that shows up in these cases is ordinarily: the certified transcript of the testimony, the signed declaration or form itself, documents that contradict it, agent notes and the FD-302 or equivalent report of an interview, and testimony from people who were present. Where a case rests on an agent’s summary of an unrecorded interview rather than a recording, that is a line of attack, not a formality.

Defending a federal perjury or false-statement charge

The defenses that work in this area are specific, and they are mostly about the record rather than about the defendant’s character.

• The question, not the answer. Under Bronston, a literally true answer to an imprecise question is not perjury, whatever the witness hoped to achieve. This begins with the transcript.
• No willfulness. Dunnigan‘s formulation is the standard: false testimony “as a result of confusion, mistake, or faulty memory” is not perjury. Long gaps in time, complex financial detail, and questions about events the witness had no reason to fix in memory are the ordinary raw material.
• Immateriality. Gaudin puts materiality to the jury. If the statement could not have influenced the decision the tribunal was making, the element fails.
• Truth. It remains a complete defense, and it is more often available than people assume once the precise wording of the question is examined.
• No oath, wrong statute. If there was no oath and no § 1746 declaration, § 1621 and § 1623 do not apply, whatever the charging language says.
• The § 1001(b) carve-out, for a party or counsel’s submissions to a judge or magistrate in a judicial proceeding.
• Proof failure on falsity — for § 1621, the two-witness rule; for any of the three, the reliability of an unrecorded interview reconstructed from notes.
• Recantation under § 1623(d), where the timing conditions are genuinely met.

Two things a defense lawyer looks at before anything else: whether there is a recording or a verbatim transcript, and whether the client had counsel present. A grand jury appearance produces a transcript; an agent interview at the front door usually does not. If you have been served with a federal grand jury subpoena or received a target letter, those are the moments when the exposure on this page is created or avoided.

How people end up here, and how not to

The most common route into a false-statement charge is not a plan to lie. It is an unplanned conversation. Agents may arrive without notice, at home or at work; the conversation is voluntary and feels informal; nobody is under oath; and the interview is reconstructed later from notes. Guessing, minimizing, or filling gaps to be helpful is how a five-year felony gets made out of a case the speaker was not even the target of.

The practical points a defense lawyer would make:

• You are not obliged to be interviewed by federal agents, and declining is not evidence of anything.
• “I don’t know” and “I don’t remember,” when true, are complete answers. Guessing under oath is where §§ 1621 and 1623 exposure begins.
• Read the document you are signing. A § 1746 declaration — the “under penalty of perjury” line — converts an unsworn writing into a sworn one.
• A proffer session is not a safe space. Proffer agreements are contracts with limits, and false statements in a proffer can cost the agreement and add exposure. Our page on proffer agreements covers how they are structured.
• If you have already given a false statement, tell your lawyer, not the agent. Fixing it is a legal problem with real timing rules, and the § 1623(d) window is narrower than it sounds.

Nothing on this page can tell you whether a particular statement was perjury, whether an enhancement will be sought, or what a court would do with it. Those turn on the transcript, the record, and the judge.

Where this sits in a federal case

Perjury exposure is not a stage of a case — it is a risk that runs alongside every stage of one, and it attaches at a different point for different people.

• During the federal investigation: this is where most of it is created. A grand jury appearance is sworn testimony and carries § 1623 exposure. An agent interview is not sworn and carries § 1001 exposure. A person who is a witness at the start of an investigation can be a defendant by the end of it purely on the strength of what he said.
• At trial: a defendant who testifies puts Dunnigan in play. Testifying is a constitutional right and losing is not obstruction, but false testimony under oath is.
• While the presentence report is prepared: materially false information to a probation officer is listed as covered conduct in the §3C1.1 commentary, and incomplete or misleading information short of a material falsehood is listed as ordinarily not covered. The distinction is decided at sentencing on the objections filed to the report.
• At sentencing: where most of this actually lands, as a contested two-level adjustment with the acceptance-of-responsibility reduction riding on the same finding.

If you are trying to understand the shape of a federal case as a whole, start at the federal court process overview. If the question is who else can be charged for someone else’s offense, that is a different set of statutes entirely, covered on our accessory page. Definitions of the terms used here are collected in the glossary.

What to do next if you are facing a perjury charge

If you have testified before a federal grand jury, given a statement to a federal agent, signed a declaration under penalty of perjury, or been told the government is considering a perjury or false-statement charge, the useful next step is a review of the actual record — the transcript, the declaration, the agent’s report — against the elements set out above. That review is what determines whether there is a Bronston problem with the question, a willfulness problem with the answer, a materiality problem with the subject matter, or a proof problem with the government’s evidence.

Elizabeth Franklin-Best, P.C. is a boutique federal criminal defense and appellate firm founded in 2019, with more than 20 years of federal and appellate criminal defense experience and a national federal practice run on an intentionally small caseload, from offices in Columbia and Mount Pleasant, South Carolina. To discuss a federal matter, call (843) 620-1100 or contact us. Nothing on this page is legal advice, and reading it does not create an attorney-client relationship.

Frequently Asked Questions About Perjury

Reviewed for legal accuracy by Elizabeth Franklin-Best, Esq., Principal Attorney·September 2026