Federal prison sentences are generally considered final once the judge imposes them. In most cases, the defendant serves the sentence that was imposed at sentencing, subject only to ordinary good-time credits and other limited adjustments. There are, however, a few important exceptions. One of those exceptions is Rule 35(b) of the Federal Rules of Criminal Procedure.
Rule 35(b) allows the government to ask a federal judge to reduce a defendant’s sentence when the defendant provides substantial assistance in the investigation or prosecution of another person after sentencing. In some cases, the reduction may be significant. In others, the reduction may be modest. Every case depends on its own facts.
Because Rule 35(b) operates after sentencing, it is often misunderstood. Defendants, spouses, parents, and other family members frequently hear terms such as “substantial assistance,” “Rule 35 motion,” or “sentence reduction,” yet struggle to find clear explanations of how the process actually works. Many people are uncertain about who may qualify, when a motion can be filed, how much time may be reduced, or what happens if the government chooses not to file a motion.
This guide explains the Rule 35(b) process in plain English. It discusses who may be eligible for a sentence reduction, what courts mean by substantial assistance, the difference between Rule 35(b)(1) and Rule 35(b)(2), and the limits on a court’s ability to review the government’s decisions. It also addresses common questions raised by defendants and their families.
If you are searching for information about a possible Rule 35(b) sentence reduction, you should understand one important principle at the outset: Rule 35(b) does not automatically apply simply because a defendant has provided information to law enforcement. The government must determine that the assistance was substantial and must decide whether to file a motion requesting a reduction. Understanding that process is the first step toward understanding whether Rule 35(b) may apply in a particular case.
The purpose of this guide is to help defendants and families understand the law, the process, and the practical realities surrounding Rule 35(b) sentence reductions in federal court.
The Complete Rule 35(b) Guide
The thirteen sections below examine each part of the Rule 35(b) process in detail. They are written to be read in order, but each one also answers a specific question on its own.
- What is Rule 35(b)?
An overview of the rule itself, and how it differs from an appeal, a Section 2255 motion, and compassionate release. - Who qualifies for a Rule 35(b) sentence reduction?
Rule 35(b) applies only in federal cases, and the assistance must genuinely benefit the government. This section explains the general principles that determine who may be eligible. - What counts as substantial assistance?
Neither the rule nor most plea agreements define the term. Prosecutors focus on the usefulness, reliability and results of the assistance rather than the effort involved. - Can cooperation after sentencing reduce a federal sentence?
Sentencing is not necessarily the end of the cooperation process. This section explains why Rule 35(b) exists and how post-sentencing assistance can still matter. - Understanding the one-year rule: Rule 35(b)(1) and Rule 35(b)(2)
The belief that all opportunity ends one year after sentencing is one of the most common misconceptions about Rule 35. The reality is more nuanced. - What happens if the government refuses to file a Rule 35 motion?
Prosecutors have broad discretion in deciding whether to seek a reduction. This section explains why motions are sometimes declined, and why silence does not always mean refusal. - Can a judge force the government to file a Rule 35 motion?
The Supreme Court’s decision in Wade v. United States set narrow limits on judicial review of a refusal to file. This section explains what those limits allow and what they do not. - How much time can Rule 35(b) remove from a sentence?
There is no fixed percentage and no chart. This section explains the factors courts commonly weigh and why comparisons to other inmates are usually misleading. - Can a Rule 35 motion be filed more than once?
A Rule 35(b) motion is not necessarily a one-time event. When cooperation continues over years, the government may revisit the question. - What families should know about Rule 35(b)
Written for spouses, parents and children trying to understand a process that is largely invisible from the outside. - Frequently asked questions about Rule 35(b)
Short answers to the questions defendants and families ask most often, from filing deadlines to whether Rule 35(b) can reach below a mandatory minimum. - Do you need a lawyer for a Rule 35 motion?
Many Rule 35 situations are straightforward. Others involve plea agreement language, multi-district cooperation, or timing questions that warrant closer review. - Rule 35 key takeaways and confidential case review
A summary of the principles covered throughout this guide, and how to request a review of a specific Rule 35 situation.
