18 USC § 3585 - Calculation of a term of imprisonment

---
identifier: "/us/usc/t18/s3585"
source: "usc"
legal_status: "official_legal_evidence"
title: "18 USC § 3585 - Calculation of a term of imprisonment"
title_number: 18
title_name: "CRIMES AND CRIMINAL PROCEDURE"
section_number: "3585"
section_name: "Calculation of a term of imprisonment"
chapter_number: 227
chapter_name: "SENTENCES"
subchapter_number: "D"
subchapter_name: "IMPRISONMENT"
part_number: "II"
part_name: "CRIMINAL PROCEDURE"
positive_law: true
currency: "119-84"
last_updated: "2026-04-21"
format_version: "1.1.0"
generator: "[email protected]"
source_credit: "(Added Pub. L. 98–473, title II, § 212(a)(2), Oct. 12, 1984, 98 Stat. 2001.)"
---


# § 3585. Calculation of a term of imprisonment

**(a)** **Commencement of Sentence.—** A sentence to a term of imprisonment commences on the date the defendant is received in custody awaiting transportation to, or arrives voluntarily to commence service of sentence at, the official detention facility at which the sentence is to be served.

**(b)** **Credit for Prior Custody.—** A defendant shall be given credit toward the service of a term of imprisonment for any time he has spent in official detention prior to the date the sentence commences—

that has not been credited against another sentence.

**(1)** as a result of the offense for which the sentence was imposed; or

**(2)** as a result of any other charge for which the defendant was arrested after the commission of the offense for which the sentence was imposed;

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**Source Credit**: (Added Pub. L. 98–473, title II, § 212(a)(2), Oct. 12, 1984, 98 Stat. 2001.)

## Statutory Notes and Related Subsidiaries

### Effective Date

Section effective , and applicable only to offenses committed after the taking effect of this section, see , set out as a note under .