18 U.S.C. § 371 — Conspiracy

Prosecutors reach for § 371 constantly, and often for a reason defendants find hard to accept: it lets the government charge a conspiracy to interfere with government operations without identifying any completed crime.

The two clauses behave very differently, and which one you are charged under changes the defense entirely.

What the statute says

18 U.S.C. § 371 punishes two or more persons who conspire either "to commit any offense against the United States, or to defraud the United States, or any agency thereof in any manner or for any purpose," where one or more of them does any act to effect the object of the conspiracy.

The two clauses, and why the difference matters

The offense clause requires an agreement to commit some other federal crime. The object offense supplies the content, and the conspiracy is derivative of it.

The defraud clause requires no other crime at all. It reaches agreements to interfere with or obstruct a lawful government function by deceit, craft, trickery, or dishonest means. Charges under this clause are often called Klein conspiracies, after a tax case, and they are common in tax, customs, procurement, and regulatory prosecutions.

The defraud clause's breadth is its defining feature — and the principal ground on which it gets challenged, since "defraud" here does not require depriving the government of money or property.

The elements

1. An agreement between two or more persons;
2. To commit a federal offense, or to defraud the United States;
3. The defendant knowingly and voluntarily joined the agreement; and
4. At least one conspirator committed an overt act in furtherance of it.

The overt act requirement distinguishes § 371 from § 846. It is a low bar — the act need not itself be criminal — but it is an element, and it must be proved.

Penalty range

Up to five years imprisonment and a fine. Where the object of the conspiracy is only a misdemeanour, the penalty cannot exceed the maximum for that misdemeanour.

Note the mismatch this creates: a § 371 conspiracy to commit a twenty-year fraud offense still carries only five years. That is why prosecutors frequently charge conspiracy and substantive counts, and why an offense-specific conspiracy statute — such as the wire fraud conspiracy provision at 18 U.S.C. § 1349 — is charged instead when available, since those carry the object offense's full penalty.

How it shows up in real cases

Section 371 appears in almost every multi-defendant federal case. In tax cases it is the vehicle for agreements to impede the IRS's assessment and collection functions. In procurement and customs cases it captures schemes to submit false information to an agency. In public corruption cases it often accompanies substantive bribery counts.

It also has a strategic function for the government: because a conspiracy count admits co-conspirator statements under Rule 801(d)(2)(E), charging conspiracy changes what evidence the jury hears about everyone at the table.

Common defenses

No agreement. Parallel conduct is not conspiracy. People pursuing similar aims independently have not agreed.

No knowledge of the unlawful object. A defendant who performed services without knowing their purpose has not joined.

Good faith. Particularly potent under the defraud clause, where reliance on professional advice or a genuine belief in lawfulness undercuts the required dishonest intent.

Withdrawal and the statute of limitations. Effective withdrawal starts the five-year clock running for that defendant, which can put an otherwise-timely charge out of reach.

Related statutes and pages

21 U.S.C. § 846 — drug conspiracy · 18 U.S.C. § 1349 — fraud conspiracy · 18 U.S.C. § 1346 — honest services · Federal conspiracy charges · Federal fraud & financial crimes