What Is a Rule 35 Hearing and How Does It Work?

A Rule 35 hearing is a federal post-sentencing proceeding under Federal Rule of Criminal Procedure 35, where a judge either corrects a clear error in a sentence that was just imposed or reduces a sentence because the defendant later provided substantial assistance to the government. It is not an appeal, it does not reopen the conviction, and it operates under strict deadlines and narrow grounds.¹

The Two Things Rule 35 Can Do

Rule 35 creates two separate paths, and they work very differently.

Rule 35(a) lets the court correct a sentence that resulted from an arithmetical, technical, or other clear error. Think of a miscalculated criminal history score or a wrong guideline range plugged in by mistake. The Advisory Committee notes describe this power as “very narrow.” It does not let the judge rethink the guidelines or reconsider whether the sentence felt right.¹

Rule 35(b) lets the court reduce a sentence when the defendant provided “substantial assistance” to the government after being sentenced. That cooperation might mean giving investigators information about other criminal activity, testifying against co-conspirators, or helping law enforcement recover evidence. This is the path that draws the most attention in practice, because the reductions can be dramatic.¹

Who Can File and When

A Rule 35(a) correction must happen within 14 days of sentencing. Either party can flag the error, and the judge can also catch and fix it on the court’s own initiative without any motion being filed. Once those 14 days pass, the window closes.¹

Rule 35(b) works differently. Only the government can file. A defendant cannot file a Rule 35(b) motion and cannot force the prosecutor to file one, which gives the government enormous leverage over anyone hoping to earn credit by cooperating after sentencing.¹

The government ordinarily has one year from sentencing to file the motion. The rule allows a later filing in limited circumstances, generally where the useful information or its value only emerged after the one-year mark. Even then, the motion has to come from the prosecutor. There is no workaround for the defendant.¹

What the Judge Weighs on a Substantial Assistance Motion

When the government files a Rule 35(b) motion, the judge does not simply approve whatever reduction the prosecutor requests. The court evaluates the cooperation using factors drawn from U.S. Sentencing Guidelines § 5K1.1: the significance and usefulness of the assistance, its truthfulness, completeness, and reliability, the nature and extent of what was provided, any risk the defendant faced in cooperating, and how promptly the information came in.²

A defendant whose testimony brought down a major drug supplier will generally see a larger reduction than one whose tip went nowhere. Judges can also take into account cooperation the defendant provided before sentencing when deciding how much credit the post-sentencing assistance deserves. There is no fixed formula, and judges differ in how much weight they give personal history or the severity of the original offense.³

Can the Sentence Go Below a Mandatory Minimum?

Yes. Rule 35(b)(4) says explicitly that the court may reduce a sentence below a statutory mandatory minimum. That provision matters most in drug trafficking cases, which account for the bulk of Rule 35(b) reductions. A defendant originally sentenced to a 10-year mandatory minimum could see that term cut substantially if the cooperation justifies it. Courts have even reduced previously imposed life sentences to a term of years through this mechanism.³

What the Proceeding Actually Looks Like

The word “hearing” is a little misleading. Rule 35 does not guarantee a courtroom proceeding. The judge reviews the motion on paper and decides whether oral argument or testimony would help. Many Rule 35(a) corrections are straightforward enough to be resolved without anyone appearing in court. Rule 35(b) motions are more likely to involve a hearing, where the government describes the cooperation and the defense argues for a specific reduction, but even those can be decided on the written submissions alone.

When a hearing does happen, the defendant does not need to attend. Federal Rule of Criminal Procedure 43(b)(4) specifically exempts Rule 35 proceedings from the general requirement that defendants be present. The defendant’s attorney appears and argues on their behalf.⁴

Possible Outcomes

The judge can grant or deny the motion. If a Rule 35(b) motion is granted, the court enters an amended judgment reflecting the reduced sentence. The size of the cut depends on the value of the cooperation and the judge’s view of the relevant factors.

For Rule 35(a), the outcome depends on the nature of the error. Because the rule allows the court to “correct” the sentence rather than only reduce it, a correction could in theory move the sentence in either direction. If a calculation mistake produced a sentence that was too low, the correction could raise it. That is a meaningful contrast with Rule 35(b), which only permits reductions.

Appealing a Rule 35 Decision

If the court denies the motion, the defendant has 14 days from entry of the order to file a notice of appeal in the district court.⁵ Appellate review is limited. For Rule 35(a), the question is whether the district court got the clear-error analysis right. For Rule 35(b), appellate courts give heavy deference to the district judge’s evaluation of the cooperation. Reversals are difficult, which is why the motion itself, and any hearing on it, is the stage that matters most.

What Rule 35 Is Not

Rule 35 is often confused with 18 U.S.C. § 3582(c), which covers entirely different situations. Section 3582(c)(1)(A) allows sentence reductions for “extraordinary and compelling reasons,” commonly called compassionate release, covering circumstances like terminal illness or advanced age after long imprisonment. Section 3582(c)(2) allows reductions when the Sentencing Commission retroactively lowers a guideline range.⁶

Rule 35(a) is for clerical and calculation mistakes caught within two weeks. Rule 35(b) is for post-sentencing cooperation. Section 3582(c) is for changed circumstances that have nothing to do with errors or cooperation. A defendant who develops a serious medical condition years into a long sentence looks to § 3582(c)(1)(A), not Rule 35. A defendant who helped prosecutors build a case against a co-conspirator after being sentenced looks to Rule 35(b), not § 3582. Picking the right provision is the first step, because filing under the wrong one wastes time and can mean missing the deadline under the one that actually fits.

1
Legal Information Institute. Federal Rules of Criminal Procedure Rule 35 – Correcting or Reducing a Sentence
2
U.S. Sentencing Commission. Substantial Assistance Report
3
U.S. Sentencing Commission. The Use of Federal Rule of Criminal Procedure 35(b)
4
Legal Information Institute. Federal Rules of Criminal Procedure Rule 43 – Defendants Presence
5
Legal Information Institute. Federal Rules of Appellate Procedure Rule 4 – Appeal as of Right When Taken
6
Office of the Law Revision Counsel. 18 U.S. Code 3582 – Imposition of a Sentence of Imprisonment