5K1 Motion: How a Substantial-Assistance Motion Works in Federal Court

What a 5K1 Motion Is

A 5K1 motion is a motion filed by the federal prosecutor under USSG § 5K1.1 asking the sentencing court to depart below the otherwise applicable guideline range because the defendant provided substantial assistance in the investigation or prosecution of another person who has committed an offense.

When a 5K1 motion is paired with a motion under 18 U.S.C. § 3553(e), the court also has limited authority to impose a sentence below an otherwise applicable statutory mandatory minimum.

Who Files It

Only the government. USSG § 5K1.1 begins "Upon motion of the government..." Cooperation by itself does not produce a motion. A cooperation agreement describes what the government has agreed to consider — not a guarantee that a 5K1 motion will be filed.

When It Is Filed

Before sentencing. The motion is filed in time for the court to consider the requested departure at the original sentencing hearing. Assistance that becomes substantial only after sentencing is addressed through Rule 35(b) instead.

What the Court Considers

USSG § 5K1.1 invites the court to weigh:

• The court's evaluation of the significance and usefulness of the assistance
• The truthfulness, completeness, and reliability of the information
• The nature and extent of the assistance
• Any injury or danger to the defendant or family arising from the assistance
• The timeliness of the assistance

The court is not bound to depart by any particular amount. Outcomes vary widely.

What the Order Looks Like in Practice

If the court grants the motion, the judgment reflects the reduced sentence as imposed. There is no separate "5K1 sentence" — the reduction is built into the term of imprisonment the court orders. The Bureau of Prisons then computes the sentence using the same rules it applies to any other sentence.

How the Reduction Translates Into Actual Time

The sentence imposed is one variable. Actual time inside a federal facility also depends on:

• Good Conduct Time (GCT)
• First Step Act Earned Time Credits
• RDAP eligibility and completion
• Residential Reentry Center (RRC) placement
• Home confinement placement

For that reason, a 12-month reduction on paper is not always a 12-month reduction in custody. See Understanding Rule 35(b) and Federal Release Date Timing for a walk-through of how post-sentence reductions interact with the BOP computation.

Questions to Discuss With Counsel

• What does the cooperation provision in the plea agreement actually require?
• Does the government anticipate filing a 5K1 motion in this case?
• Will the government also move under § 3553(e) if a statutory minimum applies?
• What is the projected guideline range before and after a potential departure?
• How would the reduced sentence be computed by the BOP under realistic assumptions?