Sentence Computation Manual(CCCA of 1984)

By Elizabeth Franklin-Best, Esq., and Christopher Zoukis, JD, MBA

Program Statement 5880.28 at a glance

Field	Value
Program Statement	5880.28
Subject	Sentence Computation Manual (CCCA of 1984). The transmittal page inside the PDF prints the subject as “Sentence Computation Manual (CCA of 1984)” — a typographical error in BOP’s own document.
Effective / current edition date	Change Notice 7, dated 7/20/99. The base transmittal page is stamped “CN-06, 7/19/99”; individual chapter pages carry earlier dates back to February 21, 1992.
Change notice	Seven, filed in front of the manual: CN-7 (7/20/99), CN-6 (7/19/99), CN-5 (12/31/98), CN-04 (6/30/1997), CN-03 (2/14/1997), CN-02 (7/29/1994), CN-01 (1/5/1993)
Supersedes / rescinds	“Directives Rescinded. None.” and “Directives Referenced. None.” (PS 5880.28 at p. 13). This manual replaced nothing; it was issued alongside the separate “Old Law” manual for pre-1987 offenses.
Governing statute	18 U.S.C. § 3585 (commencement and prior custody credit); 18 U.S.C. § 3584 (multiple sentences); 18 U.S.C. § 3624(b) (good conduct time)
Governing regulation (28 C.F.R.)	28 C.F.R. § 523.20 governs good conduct time. No regulation in 28 C.F.R. codifies the prior custody credit rules — for jail credit the binding text is the statute, § 3585(b), and the manual is the Bureau’s instruction for applying it.
Related BP forms	None. The manual works from Form USM-129, a U.S. Marshals Service custody record (PS 5880.28 at p. 43), not from a BP form.
Official PDF	PS 5880.28, Sentence Computation Manual (CCCA of 1984)

Checked against the BOP policy set · 2026-09-06.

This is the 257-page manual the Bureau of Prisons uses to turn the sentence a judge announced in open court into two dates: the day your sentence legally began, and the day the Bureau projects you will walk out. It covers when a sentence starts, how much credit you get for time already spent in jail, how multiple sentences are combined, and how good conduct time is applied.

If you want to know how the arithmetic works and what the terms on a computation sheet mean, stay here. If the Bureau has already run the numbers and you believe the answer is wrong, the place to start is challenging a BOP sentence computation, which covers how those disputes are actually raised and where they end up; and getting out walks through the sequence of release dates, halfway house and home confinement that this computation feeds into.

The rule itself: how the Bureau awards prior custody (“jail”) credit

The most-litigated, least-understood part of this manual is Chapter I, paragraph 3.c — the rules for prior custody time credit, the credit for time you already spent locked up before the federal sentence began. It is the section people call about, because it is where days go missing.

The statute is short. Section 3585(b) provides that 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— (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; that has not been credited against another sentence” (18 U.S.C. § 3585(b)). Everything below is the Bureau’s instruction to its own staff for applying those two sentences.

Reproduced below verbatim from the manual. Asterisks appear in the original as change-bars marking text revised by a Change Notice; they are omitted here.

The definitions the calculation runs on

Term	The manual’s definition, verbatim
Raw EFT	“The Raw EFT for both a federal and non-federal sentence is determined by adding the total length of the sentence to be served to the beginning date of the sentence resulting in a full term date of sentence (Raw EFT) that does not include any time credit, e.g., presentence or prior custody time or good time.”
Qualified non-federal presentence time	“Time spent in non-federal presentence custody from the date of the federal offense, that does not overlap any other authorized prior custody time credits, to the date the first sentence begins to run, federal or non-federal, is qualified non-federal presentence time.”
Date of offense (new conviction)	“The date of offense for a new conviction (as shown on the judgement and commitment) is the date on which the criminal act takes place, or the date on which the ongoing criminal activity ends, as charged in a single count. In a multiple count judgment and commitment, the earliest date of offense for the multiple counts shall be controlling for prior custody time credit determinations.”
Date of offense (revocation)	“The date of offense for a prisoner whose supervised release or probation has been revoked shall be the date of the offense which led to the original sentence.”
Official detention	“‘Official detention’ is defined, for purposes of this policy, as time spent under a federal detention order. This also includes time spent under a detention order when the court has recommended placement in a less secure environment or in a community based program as a condition of presentence detention.”

Source: PS 5880.28 at pp. 34–40 (manual pages 1‑14 through 1‑14F).

Credit under § 3585(b)(1) — detention on this federal case

The manual opens the operative list with a rule that decides a surprising number of arguments: “Any part of a day spent in official detention equals one day for credit purposes.”

Rule	The manual’s instruction, verbatim	Pin-cite
1	“Credit will be given for time spent in official detention as a direct result of the federal offense for which the federal sentence was imposed (and not as a result of a writ from another jurisdiction), provided it has not been credited against another sentence.”	p. 45
Arrest earlier than the J&C offense date	“If it can be verified that a person was in official detention on the charge for which the sentence was imposed prior to the ‘date offense concluded’ as shown on the judgment and commitment, then such time shall be awarded regardless of the date of offense on the judgment and commitment order.”	p. 46
2	“Credit will not be given for any portion of time spent serving another sentence regardless of whether the sentence is federal, state, or foreign.”	p. 47
2.a (vacated sentence)	“Time spent serving another foreign or state sentence that is vacated may be creditable as prior custody time credit provided the sentence was not vacated merely for resentencing. Any such time which is credited must be time spent after the commission of the federal offense.”	p. 47
2.b (vacated for resentencing)	“Time spent serving another federal, foreign or state sentence that is vacated merely for resentencing shall not have any effect on the SRA sentence computation until such time as the inmate is resentenced. If the resentencing results in a term which is less than the time the inmate has already served on the vacated sentence, the excess time not now credited to any other sentence shall be credited to the SRA term…”	p. 47
3 (appeal bond)	“If an SRA term is vacated solely for the purposes of a resentencing, then the date the sentence begins will be the same as the original computation. Any time spent in the community as the result of an appeal bond shall be treated as inoperative time.”	p. 48
6 (writ custody)	“Time spent in custody under a writ of habeas corpus from non-federal custody will not in and of itself be considered for the purpose of crediting presentence time. The primary reason for ‘writ’ custody is not the federal charge. The federal court merely ‘borrows’ the prisoner under the provisions of the writ for secondary custody.”	p. 52

Source: PS 5880.28 at pp. 45–52 (manual pages 1‑16 through 1‑20B).

Credit under § 3585(b)(2) — unrelated detention, and the Willis and Kayfez rules

This is the branch most people have never heard of, and it is where days are recovered.

Rule	The manual’s instruction, verbatim	Pin-cite
The general rule	“Prior Custody Credit will be given for time spent in official detention as the result of any federal, state or foreign arrest which is not related to, yet occurred on or after the date of the federal offense (as shown on the judgment and commitment) for which the SRA sentence was imposed; provided it has not been credited to another sentence.”	p. 53
Prerequisite a	“The non-related official detention must have occurred on or after the date of the federal offense for which the SRA sentence was imposed.”	p. 53
Prerequisite b	“The non-related official detention must not have been granted on another sentence. If it was applied on a state or foreign sentence, then credit is not applicable to the SRA sentence.”	p. 54
When the state gave no benefit	Failure by the non-federal government to grant credit “can be determined if: a the non-federal charges were dismissed. b non-federal probation was granted. c the federal and non-federal terms are concurrent and the Raw EFT of the non-federal term is equal to or less than Raw EFT of the federal sentence.”	p. 54
Willis credit	“Prior custody credits shall be given for any time spent in non-federal presentence custody that begins on or after the date of the federal offense up to the date that the first sentence begins to run, federal or non-federal. These time credits are known as Willis time credits (See Willis v. U.S., 449 F2d 923 (CA 5, 1971). Credit shall not be given for any time spent in non-federal presentence custody prior to the date of the SRA offense.”	p. 54
Kayfez credit	“If the non-federal and federal sentences are concurrent, the Raw EFT of the non-federal term is greater than the Raw EFT of the federal term, and if the non-federal Raw EFT, after application of qualified non-federal presentence time, is reduced to a date that is earlier than the federal Raw EFT, then a Kayfez (See Kayfez v. Gasele, 993 F.2d 1288 (7th Cir. 1993) situation exists. In such a situation, the amount of qualified non-federal presentence time … shall be applied to the non-federal Raw EFT. The federal Raw EFT shall then be reduced to equal the reduced non-federal EFT.”	pp. 56–57

Source: PS 5880.28 at pp. 53–57 (manual pages 1‑21 through 1‑22C).

The manual then works four numbered Willis examples and a Kayfez example with real dates. Worked Example No. 5, verbatim: federal offense date 03‑12‑1994; arrested by the state 03‑25‑1994; state sentence begins 04‑15‑1994; concurrent federal sentence begins 05‑10‑1994. “Time to award off the federal sentence is from 03‑25‑1994 through 04‑14‑1994 which equals 21 days” (PS 5880.28 at p. 55). Example No. 9 runs the Kayfez arithmetic and ends in “an award of 8 days of prior custody time credits” (PS 5880.28 at p. 57).

What the manual says is not “official detention”

Category	The manual’s instruction, verbatim	Pin-cite
Restrictive conditions of release	Under Koray, “a defendant is not entitled to any time credit off the subsequent sentence, regardless of the severity or degree of restrictions, if such release was a condition of bond or release on own recognizance, or as a condition of parole, probation or supervised release.”	p. 42
Halfway house on bond, home confinement, electronic monitoring	“time spent in residence in a CCC or similar facility as a result of the Pretrial Services Act of 1982 … or as a result of a condition of bond or release on own recognizance … or as a condition of parole, probation or supervised release, is not creditable”; nor is “a release condition that is ‘highly restrictive,’ and that includes ‘house arrest’, ‘electronic monitoring’ or ‘home confinement'”.	pp. 41–42
Immigration detention pending removal	“Official detention does not include time spent in the custody of the U.S. Immigration and Naturalization Service (INS) … pending a final determination of deportability. An inmate being held by INS pending a civil deportation determination is not being held in ‘official detention’ pending criminal charges.”	p. 44
Civil contempt	“Time spent serving a civil contempt sentence does not constitute presentence time credit toward any criminal sentence…”	p. 45
Release status generally	“Official detention does not include any time in a release status even though the defendant is considered ‘in custody’ for purposes of pursuing a habeas corpus petition with the court…”	p. 45
A court appearance without bail	If, after a hearing, “the defendant returns to the community without being placed on bail or on ‘own personal recognizance,’ then that defendant is not entitled to that day in court as a day in ‘official detention’… If the defendant is released on bail or on ‘own personal recognizance’ then that day is treated as a day in official detention and shall be awarded as a day of prior custody time credit.”	pp. 43–44

Source: PS 5880.28 at pp. 40–45 (manual pages 1‑14F through 1‑16).

The Koray rule the manual is applying is real Supreme Court law, not agency preference. In Reno v. Koray, 515 U.S. 50 (1995), the Court held that time spent in a community treatment center while “released” on bail under the Bail Reform Act “was not ‘official detention’ within the meaning of 18 U.S.C. § 3585(b),” and that a defendant “suffers ‘detention’ only when committed to the custody of the Attorney General; a defendant admitted to bail on restrictive conditions … is ‘released'” (Reno v. Koray).

What the Sentence Computation Manual means for you

If you are the person inside: read the prior-custody line

Ask your Unit Team for a printed sentence computation and read the prior-custody line against the four definitions above. Three checks recover most missing days. First, compare the date of offense the Bureau used against the earliest offense date on your judgment and commitment — the manual says the earliest date across multiple counts controls. Second, if you sat in a state jail after your federal offense date on charges that were later dismissed, or that produced probation, or that produced a concurrent state sentence, ask specifically whether Willis or Kayfez credit was run; those are the words that make the request legible to Inmate Systems Management. Third, if the Marshals moved you to federal court on a writ while a state case was pending, understand that the manual treats that time as state time — the fight, if there is one, is usually about whether the state actually credited it.

If the answer looks wrong, put it in writing. Start with a BP-A0148 Inmate Request to Staff to your Unit Team or ISM, and keep a copy. Do not let it sit as a hallway conversation.

If you are a family member: gathering the paper

You can help in a way the person inside cannot: gather paper. The documents that settle these disputes are the judgment and commitment order, the Form USM-129 custody record, the state jail’s inmate ledger or time-computation sheet, and any state judgment showing what credit the state applied. The Bureau will not award credit for time it believes was “credited against another sentence,” and the way you prove the state gave no benefit is with the state’s own records. Request them from the county detention center and the state department of corrections in writing; they are usually available to the person or to counsel.

One thing to be clear-eyed about: nobody outside the Bureau can tell you a release date. The computation depends on records the Bureau holds and on determinations the Bureau makes in the first instance. Be skeptical of anyone who quotes you a date.

If you are counsel: sentence computation

Two structural points govern nearly every jail-credit case. First, the district court cannot award § 3585(b) credit at sentencing — in United States v. Wilson, 503 U.S. 329 (1992), the Supreme Court held that because the statute speaks of time the defendant “has spent,” “computation of the credit must occur after the defendant begins his sentence,” and “the Attorney General, through BOP, has the responsibility for administering the sentence” (United States v. Wilson). A request to the sentencing judge to “award” credit is therefore misdirected, although a judicial recommendation on designation, or a § 5G1.3 adjustment built into the sentence itself, is not.

Second, Wilson also describes the review path: prisoners “have been able to seek judicial review of these computations after exhausting their administrative remedies,” citing the administrative-remedy regulations now codified at 28 C.F.R. part 542. That means the Bureau’s own process runs first, and the eventual judicial vehicle is a habeas petition under 28 U.S.C. § 2241 in the district of confinement rather than a motion in the sentencing court.

For aggregation questions, read the computation against 18 U.S.C. § 3584 before assuming an error: terms imposed at the same time “run concurrently unless the court orders or the statute mandates” otherwise, terms imposed at different times “run consecutively unless the court orders” otherwise, and multiple terms “shall be treated for administrative purposes as a single, aggregate term of imprisonment.” A computation that looks wrong is often § 3584(c) doing exactly what it says.

What has not changed since 1999

Nothing in the four corners of this document has changed since 1999 — and that is the single most important fact about it.

PS 5880.28 was issued with “Directives Rescinded. None” (PS 5880.28 at p. 13). It sits under seven Change Notices filed in front of it, the newest of which, CN-7 dated 7/20/99, added sentence-computation instructions for judgments containing both 18 U.S.C. § 924(c) and non‑924(c) counts, following United States v. Gonzales (PS 5880.28 at p. 1). CN-6 (7/19/99) revised the foreign-treaty-transfer computation chapter. CN-5 (12/31/98) implemented the Violent Crime Control and Law Enforcement Act of 1994 and the Prison Litigation Reform Act of 1995 amendments to § 3624(b) (PS 5880.28 at p. 3). CN-03 (2/14/1997) rewrote the prior-custody-credit chapter reproduced above, which is why those pages carry a 1997 stamp while the surrounding chapter carries 1992 and 1994 stamps.

The law underneath it has moved twice in ways the manual does not reflect:

• Good conduct time. CN-5 wrote the manual’s good conduct time chapter around the pre‑2018 version of § 3624(b), which awarded credit “beyond the time served … at the end of each year of the prisoner’s term of imprisonment.” The First Step Act replaced that language with “up to 54 days for each year of the prisoner’s sentence imposed by the court” — Pub. L. 115‑391, § 102(b)(1)(A). The current regulation, 28 C.F.R. § 523.20(b)(1), was rewritten to match in 2022. The manual’s good conduct time arithmetic is therefore superseded for every sentence the amendment reaches. We cover the current rule on the good conduct time page.
• First Step Act time credits. An entire second credit system — earned time credits under 18 U.S.C. § 3632(d)(4) — was created in 2018 and did not exist when this manual was written. It is administered under 28 C.F.R. part 523, subpart E and a separate Program Statement; see First Step Act time credits.

The prior-custody-credit rules reproduced above are the part of the manual that has aged best, because § 3585(b) itself has not been amended and Koray and Wilson still govern. Treat the good conduct time and release-date chapters with more caution, and check the statute.

Where people get stuck on time the state already credited

“The state already gave me that time”

This is the most common dead end, and it is often a paperwork problem rather than a legal one. Section 3585(b) bars credit for time “that has not been credited against another sentence,” and the Bureau reads that literally. But the manual itself supplies three ways to show the state gave no benefit: the non-federal charges were dismissed, non-federal probation was granted, or the terms are concurrent and the non-federal Raw EFT is equal to or less than the federal Raw EFT (PS 5880.28 at p. 54). The route is a BP-A0148 to ISM attaching the state records, then informal resolution, then a BP-9 within 20 calendar days of the event under 28 C.F.R. § 542.14, a BP-10 to the Regional Director within 20 calendar days of the Warden’s signed response, and a BP-11 to the General Counsel within 30 calendar days of the Regional Director’s signed response, under 28 C.F.R. § 542.15.

“I’ve asked and nothing comes back”

Silence is not the end of the road. Under 28 C.F.R. § 542.18, the Warden has 20 calendar days to respond, the Regional Director 30, and the General Counsel 40, and: “If the inmate does not receive a response within the time allotted for reply, including extension, the inmate may consider the absence of a response to be a denial at that level.” That constructive denial is what lets a stalled remedy move up rather than die. Diary the dates from the moment you file. The full sequence is on our Administrative Remedy Program page, and the request form itself on Inmate Request to Staff.

Writ time and the state-first problem

If you were in state custody and the Marshals produced you in federal court on a writ of habeas corpus ad prosequendum, the manual is explicit that “the federal court merely ‘borrows’ the prisoner” and that time is not automatically federal (PS 5880.28 at p. 52). The remedy in that situation is usually not a credit request at all — it is a request that the Bureau designate the state institution as the place of service of the federal sentence, which is a different policy with a different route. That is covered on our nunc pro tunc state designation page, and it is a designation question — the kind of issue where a consult is usually more productive than a form.

A detainer is distorting the picture

A pending detainer does not change the computation, but it changes what the computation gets you: it can block halfway house placement and the application of other credits. If a detainer is lodged, the question is whether it can be resolved, not whether it can be ignored. See detainers and the Interstate Agreement on Detainers.

Related BOP policy on sentence computation

Page	What it covers
Challenging a BOP sentence computation	How a computation dispute is actually built and raised
Getting out	The sequence from projected release date through halfway house and home confinement
Good conduct time (PS 5884.03)	The current 54‑day rule and the FSA change
First Step Act time credits (PS 5410.01)	The second credit system, earned through programming
Sentence computation, Old Law (PS 5880.30)	Offenses committed before November 1, 1987
D.C. Code sentence computation (PS 5880.33)	D.C. Code offenders in BOP custody
Nunc pro tunc state designation (PS 5160.05)	Designating a state institution for service of the federal sentence
Administrative Remedy Program (PS 1330.18)	BP‑8 through BP‑11, with deadlines
Release before a weekend or holiday (PS 5140.36)	What happens when the release date lands on a Saturday

Frequently Asked Questions About the Sentence Computation Manual

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Full text of the Program Statement

The Bureau’s own text of Program Statement 5880.28, Sentence Computation Manual (CCCA of 1984), the statement this page describes, is reproduced in full on a separate page, with page markers that match the Bureau’s published PDF so any passage can be pin-cited. Also reproduced in full is Program Statement 5800.15, Correctional Systems Manual. That is a different Program Statement, but it too governs sentence computation, which is why it is published here.

Reviewed for legal accuracy by Elizabeth Franklin-Best, Esq., Principal Attorney·September 2026