Perjury is the federal crime of knowingly making a false statement about a material fact while under oath or in a written document signed under penalty of perjury. It is a felony punishable by up to five years in prison and a fine of up to $250,000. The offense exists because courts, grand juries, and government agencies rely on truthful statements to function, and prosecutors treat it seriously even when no other crime is involved.
What Counts as Perjury
Three things have to line up before a false statement becomes perjury. Miss any one of them and the conduct may be dishonest, even unlawful under some other statute, but it is not perjury.
A Valid Oath or Signed Declaration
The person must have been under a legal duty to tell the truth. That duty arises either from taking an oath before a tribunal or officer authorized to administer one, or from signing a written document under penalty of perjury.1Office of the Law Revision Counsel. 18 USC 1621 – Perjury Generally Without that formal obligation, you are not looking at perjury.
A Knowingly False Statement
The speaker has to have known the statement was false when they made it. This is the hard line between a deliberate lie and an honest mistake. Someone who misremembers a date, confuses details, or testifies to something they genuinely believe is accurate has not committed perjury, even if the statement turns out to be wrong.2Legal Information Institute. Perjury
Opinions and subjective beliefs generally fall outside the statute because they cannot be objectively proven false. A witness who says “I thought the car was going fast” is giving a judgment, not asserting a verifiable fact.
Materiality
The lie must involve something that could influence the proceeding. The standard is whether the false statement had “a natural tendency to influence, or be capable of influencing” the decision being made.3United States Department of Justice. Criminal Resource Manual 1750 – Comparison of Perjury Statutes 18 USC 1621 and 1623 Lying about the color of your shirt on an irrelevant day probably does not qualify. Denying you were at the scene of the incident almost certainly does.
Where the Oath Requirement Reaches
Perjury is not limited to courtroom testimony. The oath requirement is satisfied in a range of settings, and most people encounter at least a few of them without appreciating the criminal exposure involved.
Depositions and grand jury proceedings carry the same legal weight as live trial testimony. Witnesses are sworn in and everything they say is recorded. A false answer during a deposition can be prosecuted as aggressively as a lie on the witness stand.
Written declarations create the broadest exposure for most people. Under 28 U.S.C. § 1746, any matter that federal law requires to be proven by a sworn statement can instead be established through an unsworn written declaration signed under penalty of perjury, and those declarations carry “like force and effect” as sworn affidavits.4Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury If you have ever signed a document containing the phrase “I declare under penalty of perjury that the foregoing is true and correct,” you accepted the same legal risk as a witness under oath.
Tax returns are another common example. A federal return carries a signature affirming the information is “true, correct, and complete,” and willfully signing a return known to contain false material information is a felony carrying up to three years in prison under a separate tax fraud statute.5Office of the Law Revision Counsel. 26 USC 7206 – Fraud and False Statements Other everyday examples include immigration forms, passport applications, affidavits in civil lawsuits, and applications for government benefits or professional licenses.
Federal Penalties and Collateral Consequences
A perjury conviction under 18 U.S.C. § 1621 or the companion false-declarations statute, 18 U.S.C. § 1623, carries a maximum sentence of five years in federal prison.1Office of the Law Revision Counsel. 18 USC 1621 – Perjury Generally6Office of the Law Revision Counsel. 18 USC 1623 – False Declarations Before Grand Jury or Court Fines can reach $250,000 for an individual under the general federal sentencing statute, which sets that ceiling for all felony convictions unless a specific statute provides a different amount.7Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine At the state level, perjury is almost universally classified as a felony, though maximum prison terms vary.
The sentence is only part of the damage. Federal law prohibits anyone convicted of a crime punishable by more than one year of imprisonment from possessing firearms, and a perjury conviction clears that threshold easily.8Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Many states also restrict voting rights for people with felony convictions, with restoration procedures that vary.
For non-citizens, a perjury conviction is treated as a “crime involving moral turpitude” under U.S. immigration law, which can make a person ineligible for a visa and trigger removal proceedings.9U.S. Department of State. 9 FAM 302.3 – Ineligibility Based on Criminal Activity
Professional licensing boards in most states treat a felony perjury conviction as grounds for suspension or revocation. Lawyers face disbarment. Doctors, nurses, accountants, real estate agents, and security professionals hold licenses that require good character or the absence of certain convictions. A single conviction can end a career in any of these fields, often for good.
Common Defenses
Literal Truth
The best-known perjury defense comes from Bronston v. United States, where the Supreme Court held that a witness who gives an answer that is literally true cannot be convicted of perjury, even if the answer was deliberately misleading or evasive.10Legal Information Institute. Bronston v. United States The burden is on the questioner to pin the witness down. As the Court put it, “precise questioning is at once the golden rule of cross-examination and the best protection against perjury.” A sloppy question that produces a technically true but unhelpful answer is a cross-examination problem, not a perjury case.
Ambiguous Questions
A genuinely ambiguous question cannot support a perjury prosecution. If it would be unreasonable to expect the person to understand what was being asked, the intent element fails.11United States Department of Justice. Criminal Resource Manual 1753 – Perjury Cases Special Problems and Defenses Courts look at context, though. If the same question was asked in several different ways during the proceeding, a defendant will have a hard time claiming confusion.
Recantation
Under 18 U.S.C. § 1623(d), someone who made a false declaration in a federal court or grand jury proceeding can escape prosecution by admitting the statement was false during the same continuous proceeding. Two conditions must be met at the time of the admission: the false statement has not yet substantially affected the proceeding, and the falsity has not already been exposed or become manifest.6Office of the Law Revision Counsel. 18 USC 1623 – False Declarations Before Grand Jury or Court The window is narrow, and the defense applies only to prosecutions under § 1623, not the broader perjury statute in § 1621.
Reliance on Legal Advice
A defendant who made a statement after fully disclosing the relevant facts to an attorney and following that attorney’s advice in good faith may be able to defeat the intent element. This is not a standalone defense but evidence that the person lacked willful intent to deceive. The defendant must show complete disclosure to counsel, specific advice about the conduct in question, and good-faith reliance on that advice.12Ninth Circuit District and Bankruptcy Courts. 5.10 Advice of Counsel
Related Charges Often Confused With Perjury
Subornation of Perjury
Convincing someone else to lie under oath is its own crime. Under 18 U.S.C. § 1622, anyone who “procures another to commit any perjury” faces the same penalty as the person who actually lied: up to five years in prison, a fine, or both.13Office of the Law Revision Counsel. 18 USC 1622 – Subornation of Perjury Prosecutors often use this charge against attorneys, employers, or co-defendants who coach witnesses to give false testimony.
False Statements to Federal Agents
Lying to a federal agent is a crime even when no oath is involved. Under 18 U.S.C. § 1001, knowingly making a false statement about a material fact in any matter within the jurisdiction of the federal government is a felony punishable by up to five years in prison, with the maximum rising to eight years when the statement involves terrorism or certain sex offenses.14Office of the Law Revision Counsel. 18 USC 1001 – Statements or Entries Generally The statute reaches casual conversations with FBI agents, written forms submitted to federal agencies, and even concealing material facts through a “trick, scheme, or device.” Plenty of people have been convicted under § 1001 for lying during an interview they did not realize carried criminal consequences.
Statute of Limitations
The federal government has five years from the date of the offense to bring perjury charges, under the general federal statute of limitations for non-capital offenses, 18 U.S.C. § 3282.15Office of the Law Revision Counsel. 18 USC 3282 – Offenses Not Capital State deadlines for felony perjury typically range from three years to no limit at all, depending on the jurisdiction. The clock starts on the date the false statement was made, not the date it was discovered.