Federal Sentence Planning Series

5K1.1 Explained: The Substantial-Assistance Guideline in Plain Language

USSG § 5K1.1 sets the framework for downward departures based on substantial assistance. This guide walks through the guideline text, the five factors the court may weigh, and how 5K1.1 fits with § 3553(e) and Rule 35(b).

Published February 1, 2026

What § 5K1.1 Says

USSG § 5K1.1, Substantial Assistance to Authorities, provides that upon motion of the government stating that the defendant has provided substantial assistance in the investigation or prosecution of another person who has committed an offense, the court may depart from the guidelines.

The guideline then lists factors the court may consider in deciding whether to depart, and how much.

The Five Factors

  1. Significance and usefulness of the defendant's assistance, taking into consideration the government's evaluation of the assistance rendered.
  2. Truthfulness, completeness, and reliability of any information or testimony provided.
  3. Nature and extent of the defendant's assistance.
  4. Any injury suffered, or any danger or risk of injury, to the defendant or the defendant's family resulting from the assistance.
  5. Timeliness of the defendant's assistance.

What § 5K1.1 Does Not Do

  • It does not authorize the court to depart on its own, a government motion is required.
  • It does not authorize a sentence below a statutory mandatory minimum. That requires a separate motion under 18 U.S.C. § 3553(e).
  • It does not set a fixed reduction. The court has wide discretion.
  • It does not apply to assistance that becomes substantial only after sentencing, that is handled under Rule 35(b).

How § 5K1.1 Fits With Other Provisions

  • USSG § 5K1.1, guideline departure for substantial assistance, pre-sentencing.
  • 18 U.S.C. § 3553(e), statutory authority to go below a mandatory minimum, also on government motion for substantial assistance.
  • Fed. R. Crim. P. 35(b), post-sentencing reduction for substantial assistance, on government motion.

Practical Takeaways

  • A 5K1 reduction is a court decision based on the government's motion.
  • The size of any departure varies case-by-case.
  • The reduced sentence is then computed by the BOP using its standard rules, GCT, FSA credits, RDAP, RRC, and home confinement all still apply.

Common questions about USSG 5K1.1

Where is Section 5K1.1 in the Sentencing Guidelines manual?

It sits in Chapter Five, Part K, which covers departures. Part K collects the grounds on which a court may sentence outside the guideline range, and Section 5K1.1 is the substantial-assistance provision within that part of the manual.

Is a 5K1.1 departure measured in offense levels?

Not by rule. Some courts describe a departure as a number of offense levels and others simply state a reduced term of imprisonment. The guideline itself sets no unit of measurement and leaves the extent of the departure to the sentencing judge.

Can a judge deny a 5K1.1 motion?

Yes. A government motion permits a departure but does not require one. The judge evaluates the assistance under the listed factors and the overall sentencing analysis, and may depart fully, depart less than requested, or decline to depart at all.

Does Section 5K1.1 work the same way in every federal district?

The guideline text is national, but practice is not uniform. Districts and individual prosecutors differ in when they file, how they describe assistance, and what they recommend. Judges also differ in how much weight they give each of the listed factors.

Educational purpose only. Federal Sentence Help is not a law firm. Nothing on this page constitutes legal advice.

Sources & References

Frequently Asked Questions

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