A federal prison sentence generally cannot be changed simply because a judge later prefers a shorter term. 18 USC 3582(c) identifies limited modification routes, including compassionate release, reductions authorized by Rule 35 or another statute, and qualifying retroactive guideline reductions. Each route has different filing authority and requirements. [1]
Compassionate release under Section 3582(c)(1)(A)
A defendant can move after fully exhausting the specified administrative rights or after thirty days have elapsed from the warden’s receipt of the request, whichever is earlier. Preserve proof of what the warden received and when. A request sent to an unrelated office may not establish the statutory trigger. [1]
The court must consider the applicable Section 3553(a) factors and the requirements concerning extraordinary and compelling reasons and applicable Sentencing Commission policy statements. The statute also contains a specialized age-and-service provision. A medical diagnosis or family hardship does not automatically establish entitlement to release. [1][2]
Rule 35(b) concerns substantial assistance
Rule 35(b) ordinarily requires a government motion made within one year of sentencing based on substantial assistance after sentencing. Later government motions are permitted only under the rule’s specified information and timing conditions. A defendant cannot replace the government’s required motion simply by describing cooperation in a letter to the judge. [3]
The rule allows the court, when acting under that provision, to reduce a sentence below a statutory minimum. That authority should not be assumed to apply to every other kind of sentence-reduction motion. [3]
Section 3582(c)(2) concerns lowered guideline ranges
This route applies when the sentence was based on a range subsequently lowered by the Sentencing Commission and the reduction is consistent with applicable policy statements. Not every new guideline amendment is retroactive, and a change to a guideline does not necessarily lower this defendant’s applicable range. [1]
Review the original sentencing calculation, statutory minimums, amendment, and governing policy statement before predicting a new term. A motion under this provision is not an unrestricted resentencing of every issue in the original case.
Choose the route before drafting
- Identify the statutory basis and who may file.
- Collect the judgment and original sentencing record.
- Document any administrative request and response.
- Address the relevant sentencing factors and requested reduction.
See sentencing fact hearings for disputed sentencing evidence. postconviction appeal permissions concerns a different procedure and should not be treated as a substitute for a valid sentence-reduction route.
Primary sources
- 18 USC 3582 – Imposition of a Sentence of Imprisonment
- 18 USC 3553 – Imposition of a Sentence
- Federal Rules of Criminal Procedure: Rule35(b)
Sources checked: October 31, 2026.