The Bureau of Prisons' August 31, 2026 interim final rule moves the First Step Act time-credit earning-start boundary: effective September 30, earning can begin when the federal sentence commences, including receipt in custody awaiting transportation, rather than only on arrival or voluntary surrender at the designated BOP facility. It also clarifies that a foreign sentence does not bar application when the U.S. Parole Commission has determined an equivalent U.S. Code sentence.
It does not award credits merely because a sentence was imposed, make every inmate eligible, or convert credits automatically into release. Eligibility, assigned programming, successful participation, accrual, application, and release remain different states.
The question this map answers
What changes on September 30 in the First Step Act time-credit path, which gates remain, and why is an earlier earning start not the same thing as a new release date?
MyMap compared the August 31 rule with the eCFR and cited statutes at 4:08 AM Pacific Time that day. The eCFR still showed the pre-effective text; the Federal Register supplies the September 30 replacement.
In this map, earning start is the earliest point after which successful completion of assigned evidence-based recidivism reduction programming or productive activities can generate credits. Accrual is the balance earned under the applicable rate. Application is the later use of accrued credits toward prerelease custody or early transfer to supervised release. Treaty transfer means an offender sentenced in another country and transferred to U.S. custody under an applicable treaty; it is not every person with foreign criminal history.
The current parenthetical waits for the designated facility
Current 28 CFR 523.42(a) says an eligible inmate begins earning after the term of imprisonment commences, which it parenthetically defines as the date the inmate arrives or voluntarily surrenders at the designated Bureau facility where the sentence will be served.
That parenthetical can leave a period between federal sentencing and designation outside the regulatory earning window, even when the person is already in federal custody awaiting transportation. BOP reports that inmates are generally in U.S. Marshals Service custody during this interval and may be housed in local, county, regional, or federal detention facilities.
The agency's analysis of newly committed inmates with sentences beginning in 2023–2025 found an average 66.06 days from sentencing to arrival at the designated facility. BOP estimates that interval could correspond to an average 23.81 days of potential credits under the revised boundary. Those figures are agency averages and projections, not an individual entitlement.
The revised sentence-start state follows 18 U.S.C. 3585(a)
The rule removes the designated-facility parenthetical. Revised § 523.42(a) will say only that an eligible inmate begins earning after the term of imprisonment commences.
BOP explains that the remaining phrase follows 18 U.S.C. 3585(a): a federal sentence commences when the defendant is received in custody awaiting transportation to the official detention facility where the sentence will be served, or when the defendant voluntarily arrives there. A sentence cannot commence before it is imposed.
The map therefore shows two ways into the same sentence-commencement state: receipt in custody for service of the federal sentence while awaiting transport, and voluntary surrender at the serving institution. It does not draw an edge from a sentencing date to automatic accrual because the rule says programming and successful participation still matter.
Earning requires more than the clock starting
The Act and current regulations require an eligible inmate to successfully participate in assigned evidence-based recidivism reduction programming or productive activities. Assignment is based on assessed needs; confinement alone does not create credits.
The ordinary rate is 10 days of credit for every 30 days of successful participation. An inmate assessed at minimum or low recidivism risk who maintains or reduces that risk over two consecutive assessments earns another five days per 30 days, producing the 15-day rate.
This is why the map separates four records: sentence commencement, eligibility, participation interval, and accrual posting. An earlier start expands the period in which qualifying participation may count; it does not populate the participation record or decide the rate by itself.
Treaty-transfer prisoners get a narrower application clarification
Current § 523.44(a)(3) generally bars application of First Step Act credits when a term is based on an offense under laws other than the U.S. Code. The paragraph already says that this bar does not prevent application authorized by the District of Columbia Code for a D.C. Code sentence.
The revised text adds another boundary. The paragraph will not bar application for a term imposed in a foreign country when the U.S. Parole Commission has determined an equivalent U.S. Code sentence under 18 U.S.C. 4106A. BOP says this codifies current practice for treaty-transfer inmates.
Three caveats matter. First, an equivalent U.S. Code determination is a required relationship; physical transfer to BOP custody alone does not establish it. Second, the new sentence says the non-U.S.-Code paragraph will not bar application—it does not erase other eligibility or application requirements. Third, the order describes treaty-transfer prisoners as U.S. citizens or nationals transferred under treaty, not all foreign-sentenced prisoners worldwide.
Applying credits is a different state from earning them
Accrued credits can be applied toward prerelease custody or early transfer to supervised release only through the separate requirements in § 523.44 and the governing statute. The destination and timing depend on factors including credit balance, remaining term, recidivism risk, sentence structure, and statutory exclusions.
The interim final rule does not rewrite all of those gates. It revises the earning-start sentence and the non-U.S.-Code application paragraph. For that reason, MyMap does not draw “new start date → release.” It draws “new start date → eligible period for successful participation → accrued balance → separate application review.”
BOP estimates annual savings of about $54.13 million from the expanded accrual period, using average eligible populations, 23.81 potential days, and published daily-cost inputs for BOP facilities, Residential Reentry Centers, and home confinement. That estimate is a regulatory impact calculation, not a promise that a named person will leave custody 23.81 days earlier.
The rule is final for an effective date but still requests comments
The agency issued an interim final rule, effective September 30, 2026, and requested comments by the same date. BOP says advance notice and comment were unnecessary because the revisions relieve restrictions and align the regulation with the statute, court decisions, and current practice.
That status differs from a proposed rule with no decided text. The amendments have a stated effective date, but the pre-effective text remains current until then. Comments can still inform later agency action. A map or case calculation should carry both the rule version and the date being evaluated.
Confirmed, derived, and still unknown
The controlling sources confirm the current designated-facility parenthetical; its removal effective September 30; the two sentence-commencement routes described by BOP; continued programming and successful-participation requirements; 10- and 15-day accrual rates; the foreign-sentence equivalence clarification; the existing D.C. Code boundary; the comment deadline; the 66.06-day average designation interval; the 23.81-day average potential-credit estimate; and BOP's approximately $54.13 million annual savings estimate.
MyMap derives the state machine separating start, eligibility, participation, accrual, application, and destination. It also derives the “not a release-date change” warning by preserving the downstream gates that the rule does not amend.
The sources leave unknown any named inmate's eligibility, program assignments, successful-participation dates, risk assessments, credit balance, equivalent U.S. Code determination, application date, prerelease placement, supervised-release eligibility, recalculated release date, or effect of later comments and litigation. The rule cites recent cases but does not resolve every individual sentence-computation dispute.
Reproducible mapping method and next step
For one case, create a dated row for sentence imposition, federal-custody receipt, voluntary surrender if applicable, designation and arrival, each assigned program or activity, each successful participation interval, risk assessments, statutory exclusion review, credit accrual postings, and application decisions. For a treaty transfer, attach the U.S. Parole Commission's equivalent-code determination. For a D.C. Code sentence, record the separate authorizing basis.
Run the record through the rule version in force on each date. Before September 30, preserve the current parenthetical; on and after the effective date, use the revised commencement text and check agency implementation. Never substitute the 66.06-day average or 23.81-day estimate for the person's custody and participation evidence.
The practical next step is to audit the interval between sentence commencement and designated-facility arrival for documented qualifying programming, then verify BOP's implementation and the complete application gates. This map explains the rule's states and is not an individual sentence calculation or legal advice.
References
The controlling amendment is BOP's First Step Act Time Credits—Revisions. Compare the current 28 CFR part 523, subpart E with 18 U.S.C. 3585, the First Step Act earning provisions in 18 U.S.C. 3632, and the treaty-transfer equivalence procedure in 18 U.S.C. 4106A. Accessed August 31, 2026.
Cite this article
Park, Elena. “BOP moved the credit start, not every release date.” MyMap Research, August 31, 2026. https://www.mymap.ai/blog/first-step-act-time-credit-state-map