What Is the Statute of Limitations for Conspiracy?

The statute of limitations for conspiracy under federal law is five years for most charges, and that window runs from the last act any member of the group took to push the plan forward, not from the day the agreement was formed.1Office of the Law Revision Counsel. 18 U.S.C. 3282 – Offenses Not Capital Certain conspiracies carry six, seven, eight, or ten years, and a few carry no time limit at all. State deadlines are set separately and vary widely.

When the Five-Year Clock Starts

The general federal conspiracy statute makes it a crime for two or more people to agree to commit a federal offense or to defraud the United States, provided at least one of them takes a step to carry out the plan.2Office of the Law Revision Counsel. 18 U.S.C. 371 – Conspiracy to Commit Offense or to Defraud United States Because the statute sets no limitations period of its own, the default five-year rule for non-capital federal crimes controls.

Conspiracy differs from most crimes because it isn’t a single act. It’s an ongoing agreement. The Supreme Court held in Fiswick v. United States that the overt acts alleged and proved mark the duration of the conspiracy, and the statute of limitations runs from the last overt act.3Justia. Fiswick v. United States, 329 U.S. 211 (1946)

An overt act is any step taken to advance the conspiracy’s goal, and it doesn’t need to be illegal on its own. Buying supplies. Making a phone call. Scouting a location. Moving money. Each time any member takes one of these steps, the clock resets for everyone in the group. Three people who agreed in January to rob a store, where one of them drives past the target in June to check the security, have reset the five-year window to June. The agreement date no longer matters.

That mechanic hands prosecutors a real advantage. A conspiracy formed years ago stays prosecutable so long as someone kept pushing the plan within the last five years, and defendants sometimes discover that an act they barely knew about, taken by a co-conspirator they rarely spoke with, is what keeps the case alive.

Cover-Up Acts Don’t Count

There is a hard limit on what qualifies. Once the conspiracy has achieved its central goal, steps taken merely to hide the crime do not extend its duration. The Supreme Court drew that line in Grunewald v. United States, refusing to let the clock stretch indefinitely just because conspirators kept quiet and covered their tracks after the main objective was done.4FindLaw. Grunewald v. United States, 353 U.S. 391 (1957)

So if a fraud scheme was completed in 2020, the fact that the participants stayed silent through 2024 doesn’t push the deadline forward. Prosecutors sometimes argue that concealment was built into the original agreement, but courts treat that argument skeptically without strong evidence.

Drug Conspiracies Work a Little Differently

Not every conspiracy statute requires an overt act. The general statute under 18 U.S.C. § 371 does. The federal drug conspiracy statute, 21 U.S.C. § 846, does not; the crime is complete the moment the agreement is formed, as the Supreme Court confirmed in United States v. Shabani.

For limitations purposes, that means the clock runs from when the conspiracy ended, whether because the goal was accomplished, the plan was abandoned, or the last member withdrew. Prosecutors focus on when the agreement stopped rather than on a specific identifiable act.

Longer Deadlines for Specific Conspiracies

Congress has written longer limitation periods into several categories of conspiracy. These override the five-year default.

The financial institution provision reaches broadly. It explicitly covers conspiracies and sweeps in wire fraud and mail fraud whenever a bank or similar institution is among the victims. The same scheme without a financial institution victim would fall back to the standard five years.

Conspiracies With No Time Limit

Any offense punishable by death can be charged at any time, with no limitations period.9Office of the Law Revision Counsel. 18 U.S.C. 3281 – Capital Offenses A conspiracy to commit such an offense inherits that open-ended exposure. Conspiracies to commit certain acts of terrorism, treason, or espionage carrying a potential death sentence can be prosecuted decades after the last act in furtherance. Terrorism conspiracies that resulted in death or a foreseeable risk of death also have no deadline under their own statute, independent of whether the death penalty applies.

When the Clock Can Be Paused

Two situations commonly suspend the running of the limitations period.

Fleeing from Justice

Federal law provides that no statute of limitations applies to any person who is fleeing from justice.10Office of the Law Revision Counsel. 18 U.S.C. 3290 – Fugitives from Justice If a co-conspirator leaves the country or hides within the United States to avoid prosecution, the clock stops during the period of flight and picks up where it left off when the person returns or is caught. Three years on the run does not buy three years of protection.

Foreign Evidence Requests

When prosecutors need evidence held in another country, they can ask a federal court to suspend the limitations period while the foreign government processes the request. The total suspension cannot exceed three years, and if the foreign government responds quickly, the extension is capped at six months beyond when the limitations period would otherwise expire.11Office of the Law Revision Counsel. 18 U.S.C. 3292 – Suspension of Limitations to Permit United States to Obtain Foreign Evidence This comes up often in international fraud and money laundering conspiracy cases.

Withdrawal as a Defense

A person who withdrew from the conspiracy before the limitations period began has a complete defense. The catch is that the defendant has to prove it. The Supreme Court held in Smith v. United States that withdrawal is an affirmative defense, and the defendant must prove it by a preponderance of the evidence, even when raised specifically to invoke the statute of limitations.12Justia. Smith v. United States, 568 U.S. 106 (2013)

Proving withdrawal generally requires some affirmative step to disassociate: notifying co-conspirators that you’re done, reporting the scheme to law enforcement, or taking clear action inconsistent with continued participation. Drifting away or going quiet usually isn’t enough. If you can show you withdrew more than five years before charges were filed, prosecution is barred as to you, even if the conspiracy continued among the remaining members.13Ninth Circuit Court of Appeals Jury Instructions. Withdrawal From Conspiracy

State Conspiracy Charges Are Separate

Everything above governs federal prosecutions. Conspiracy is also a crime under every state’s criminal code, and state deadlines vary considerably. Many states tie the conspiracy limitations period to the target offense: a conspiracy aimed at a felony with a four-year window carries a four-year window itself. Other states set a fixed period for all conspiracy charges regardless of the target. For the most serious crimes, including murder in most states, no limitations period applies, and conspiracy to commit murder typically inherits that unlimited exposure. Felony conspiracy deadlines across states generally fall between three and six years, but the only reliable answer comes from the criminal code of the state where the conduct occurred.