RDAP time off

RDAP sentence reduction under 18 U.S.C. § 3621(e): up to 12 months

RDAP can take up to 12 months off a federal sentence, but only if you finish all three parts of the program and BOP finds you eligible. The law, 18 U.S.C. § 3621(e), says BOP "may" reduce your time. It does not have to, and the cut can be less than 12 months.

As seen in

By Brandon Sample

Last revised: November 9, 2026

Key points

The law caps the RDAP reduction at one year and leaves the choice to BOP.
BOP limits it by sentence length: up to 6 months for sentences of 30 months or less, 9 months for 31 to 36 months, and 12 months for 37 months or more.
You get the time off only after you finish all three parts, including community treatment.
The cut can shrink or go away if you start late, need more time in community treatment, or leave the program.
People held for immigration authorities, and some other groups, cannot get the time off.

What the law says

The RDAP time off comes from one sentence of federal law:

"The period a prisoner convicted of a nonviolent offense remains in custody after successfully completing a treatment program may be reduced by the Bureau of Prisons, but such reduction may not be more than one year from the term the prisoner must otherwise serve."
18 U.S.C. § 3621(e)(2)(B)

People call this "3621(e)" or the "RDAP early release." Three parts of that sentence matter:

"Nonviolent offense." Only people convicted of a nonviolent offense can get it. BOP decides what counts. The eligibility guide explains how.

BOP's rule also covers some people serving D.C. Code sentences (28 C.F.R. § 550.55(a)(1)(ii)). See RDAP for D.C. Code sentences.
"May be reduced." BOP can say no. The Supreme Court read "may" this way in Lopez v. Davis: if you meet the law's two conditions, the law "instructs that the BOP 'may,' not that it must, grant early release" (531 U.S. 230, syllabus).
"Not more than one year." One year is the most anyone can get.

The cut is to your time in custody. It does not change the sentence the judge gave you.

How much time off: BOP's sentence-length table

BOP limits the reduction based on the prison term the court imposed. The rule allows this (28 C.F.R. § 550.55(c)(2)). BOP's policy sets the limits (P5331.02, § 11, p. 7):

Sentence length	Most time off
30 months or less	No more than 6 months
31 to 36 months	No more than 9 months
37 months or more	No more than 12 months

The limits are "not pro-rated by days." The policy's example: a sentence of 36 months and any number of days still gets no more than 9 months (P5331.02, § 11, p. 7).

If a court later changes your sentence length, BOP recomputes. The policy's example: a 36-month sentence cut to 24 months means no more than 6 months off.

BOP's DSCC makes the official release-date computation. If you think a computation is wrong, the notices and records behind it are needed to check it.

Designation and Sentence Computation Center (DSCC): The BOP office that computes release dates and checks offenses for early release.

When BOP decides if you are eligible

BOP decides in steps, starting before you begin RDAP (P5331.02, §§ 8–10, pp. 5–7):

First check. The Drug Abuse Program Coordinator (DAPC), the staff member who runs drug treatment, checks for things that rule you out. Examples are a past § 3621(e) release or a detainer that would block community treatment.
Offense review. If nothing rules you out, DSCC lawyers review your current and prior offenses. They "ordinarily have 30 working days."
Notice to you. You sign a Notice of RDAP Qualification form that shows your early release status.
Provisional date. When you start RDAP, the DAPC asks DSCC to compute a provisional early release date. Each step has a 15-working-day target.
Final review. About 30 days before you go to a halfway house, your unit team checks that every condition is met (P5331.02, § 12.a(9), p. 10).
Certification. When you finish community treatment, BOP's community treatment supervisor certifies to DSCC that you completed all of RDAP (P7430.03, § 6, p. 8).

Unit team: The BOP staff on your housing unit who manage your case and plan your release.

Why your reduction can be less than 12 months

Even if you are eligible, several things can shorten the time off:

Sentence length. The table above caps it at 6 or 9 months for shorter sentences.
Starting late. BOP gives priority based on how close you are to release (18 U.S.C. § 3621(e)(1)(C)). BOP tries to move people into RDAP with enough time to finish, "ordinarily at 24 months" before release (P5330.11, ch. 2, § 2.5.5, p. 10). If you start later, less time may be left to cut.
Extra time in treatment. If you need more time in the unit for clinical or administrative reasons, BOP sends DSCC a new date form (P5331.02, § 12.a(2), p. 8).
Community treatment. If you cannot finish community treatment by your planned date, BOP "may adjust provisional release dates by the least amount of time necessary" (28 C.F.R. § 550.55(c)(3)).
Short halfway-house time. BOP policy says people approved for less than 120 days in a halfway house or home confinement ordinarily cannot finish community treatment, "and are, therefore, ineligible for early release" (P5330.11, ch. 2, § 2.5.15, p. 21).
Leaving the program. If you withdraw, are expelled, or fail follow-up or community treatment, you can lose the early release (P5331.02, § 12.a(4), p. 8). See the expulsion guide.

Immigration detention and detainers

People held for Immigration and Customs Enforcement (ICE) cannot get the early release. The rule lists "Immigration and Customs Enforcement detainees" first among the excluded groups (28 C.F.R. § 550.55(b)(1)).

A detainer can also matter. In its first check, the DAPC looks for "a detainer that will prohibit completion of the community treatment component of the RDAP" (P5331.02, § 8.b, p. 5).

BOP policy gives the example of a person who will be deported. That person "is unqualified for the RDAP" because they cannot go to a halfway house, but can take the non-residential drug program (P5330.11, ch. 2, § 2.5.1, p. 9).

If a detainer is lodged after you start RDAP, the policy says you "may remain in treatment" (P5330.11, ch. 2, § 2.5.1, p. 9). If a detainer is dropped, the DAPC can change you from ineligible to eligible when no other bar applies (P5331.02, § 12.a(3), p. 8).

Can RDAP be combined with other early release?

Other kinds of early release follow their own rules, and how they fit together depends on your sentence computation. We cover only the RDAP part here.

First Step Act time credits. The First Step Act did not change the one-year limit in 18 U.S.C. § 3621(e). BOP lists RDAP as a program that can also earn First Step Act time credits (BOP First Step Act Approved Programs Guide, p. 19). Under BOP's time-credit policy, a person who is eligible for the RDAP early release may receive both.

BOP applies the § 3621(e) reduction first, then the time credits. Credits can move up the start of supervised release by up to 12 months, if the judge imposed supervised release (18 U.S.C. § 3624(g)(3)). If there is not enough time left for both, BOP applies fewer credit days toward that early transfer so there is still room for at least a 120-day community placement for treatment (P5410.01 § 11, p. 18).

That limits how many credits are applied. The policy does not call it a loss of earned credits. The rules for earning and applying the credits are separate from the rules for RDAP, and how the Act and RDAP work together is covered at firststepact.com.
Halfway house and home confinement time. One RDAP reward is "consideration for the maximum period of time in a community-based treatment program" (28 C.F.R. § 550.54(a)(1)(ii)). For the general rules, see Federal halfway houses (RRCs) on sentencing.net and Federal home confinement on sentencing.net.
Early release in general. See Early release from federal prison on sentencing.net.

Which release date can you rely on?

Rely only on BOP's written computation, and check which date it shows. A halfway-house date, a provisional § 3621(e) date and a full-term date are different dates. A family calendar or an online estimate is not BOP approval.

These are different dates:

the date you move to a halfway house or home confinement
the date community treatment should end
the provisional § 3621(e) release date
the date you start supervised release
the full-term date

Keep the written computation and the notices about your RDAP status.

Ask whether the computation was updated if the court changes the sentence, an offense is classified differently, a detainer is dropped, or your time in the program is interrupted. The most time in the table above is a limit, not a promise.

Sources

Does the RDAP time off in your records look wrong?

The answer can depend on the sentence, how the offense is classified, your program status, the community treatment schedule and other credits. You can request a consultation to talk about whether we can help look into it. BOP makes the official computation.

Frequently asked questions

How much time off do you get for RDAP?

Up to 12 months, and BOP decides. BOP policy limits it by sentence length: no more than 6 months for a sentence of 30 months or less, 9 months for 31 to 36 months, and 12 months for 37 months or more (P5331.02, § 11, p. 7). The law says the reduction "may not be more than one year" (18 U.S.C. § 3621(e)(2)(B)).

What is a 3621(e)?

It is the part of federal law that created RDAP and lets BOP cut up to one year from the custody time of a person convicted of a nonviolent offense who finishes the program (18 U.S.C. § 3621(e)(2)(B)). People often say "3621(e)" to mean the RDAP early release itself.

Will RDAP reduce my sentence?

It does not change the sentence the judge gave you. It can reduce how long you stay in BOP custody, if BOP finds you eligible and you finish all three parts (18 U.S.C. § 3621(e)(2)(B); 28 C.F.R. § 550.55(a)). The law says BOP "may" reduce the time, so it is not automatic.

When do you get the RDAP early release?

After you finish community treatment, the last part of RDAP. BOP policy says early release comes "Following completion of" community treatment, within the sentence-length limits (P5331.02, § 11, p. 7). BOP may push the date back by the least time needed for you to finish that treatment (28 C.F.R. § 550.55(c)(3)).

Can a non-citizen get RDAP time off?

Not if held for Immigration and Customs Enforcement. The rule lists "Immigration and Customs Enforcement detainees" as not eligible for early release (28 C.F.R. § 550.55(b)(1)). BOP policy also says a person who will be deported cannot take RDAP if they cannot go to a halfway house for community treatment, but can take the non-residential program (P5330.11, ch. 2, § 2.5.1, p. 9).

This page is general information about federal law, not legal advice for your case. BOP decides who gets into RDAP and who gets time off. Read the disclaimer.