Sentence credits in the federal prison system come in two separate forms, and together they can meaningfully shorten the time an inmate spends behind bars. Good conduct time under 18 U.S.C. § 3624(b) takes up to 54 days per year off the sentence itself for staying out of trouble. First Step Act earned time credits under 18 U.S.C. § 3632 add 10 to 15 days for every 30 days of approved programming, and those credits move eligible inmates into a halfway house, home confinement, or supervised release earlier than their projected release date. The two tracks have different rules, different eligibility, and different effects on a release date, and families trying to estimate when someone comes home routinely confuse them.
The Two Credit Tracks
Good conduct time (GCT) is passive. You earn it by complying with institutional rules, and it reduces the sentence itself.1Office of the Law Revision Counsel. 18 USC 3624 – Credit Toward Service of Sentence for Satisfactory Behavior
First Step Act time credits (FTCs) are active. You earn them by completing evidence-based recidivism reduction programs and productive activities, and they do not shorten the sentence. Instead, they move an inmate earlier into prerelease custody—a halfway house or home confinement—or into supervised release.2Office of the Law Revision Counsel. 18 USC 3632 – Development of Risk and Needs Assessment System The Bureau of Prisons has confirmed that FTCs “are not the same as GCT credits and will not be earned or applied in the same manner.”3Federal Register. Good Conduct Time Credit Under the First Step Act
Both tracks reduce time inside a federal facility. They just do it through different mechanisms, and that difference matters when you’re trying to project a release date.
Good Conduct Time: Up to 54 Days a Year
An inmate serving more than one year, but not a life sentence, can earn up to 54 days of good conduct time for each year of the sentence imposed by the court. That works out to roughly 15% of the total sentence.1Office of the Law Revision Counsel. 18 USC 3624 – Credit Toward Service of Sentence for Satisfactory Behavior For a 10-year sentence, the maximum reduction is about 540 days.
Good conduct time is not automatic. The BOP must find that the inmate displayed “exemplary compliance with institutional disciplinary regulations” during each year to award the full 54 days. The statute is also unforgiving on timing: credit that isn’t earned in a given year cannot be awarded retroactively. A year of bad behavior permanently costs that year’s credit.
First Step Act Earned Time Credits
FTCs accrue at 10 days for every 30 days of successful participation in approved programming. Inmates classified as minimum or low recidivism risk who have not increased their risk level across two consecutive assessments earn an enhanced rate: 15 days for every 30 days of participation.2Office of the Law Revision Counsel. 18 USC 3632 – Development of Risk and Needs Assessment System Keeping a low PATTERN score effectively cuts the credit-earning timeline by a third.
Who Qualifies
Not everyone in federal prison can earn FTCs. The statute disqualifies inmates convicted of a long list of offenses, including most homicide offenses (with exceptions for manslaughter), all sexual abuse offenses, terrorism, espionage, kidnapping, carjacking resulting in serious injury, and certain high-level drug trafficking charges.4Federal Bureau of Prisons. First Step Act – Disqualifying Offenses Repeat felons convicted of possessing a firearm and inmates convicted of offenses involving human trafficking are also excluded.5Federal Bureau of Prisons. First Step Act Overview
Disqualified inmates can still participate in programs and still earn good conduct time. They just can’t convert programming into days off their federal sentence.
How PATTERN Risk Scores Affect Application
Earning FTCs is one thing. Having them applied toward earlier release is another. To use accumulated credits for transfer to prerelease custody, an inmate must maintain a minimum or low recidivism risk score across their last two consecutive PATTERN assessments.6Federal Bureau of Prisons. First Step Act of 2018 – Time Credits Procedures for Implementation of 18 USC 3632(d)(4) The system reassesses risk periodically, factoring in program completion and disciplinary history.
Inmates with medium or high PATTERN scores can still earn credits, but applying them happens only in what BOP policy calls “highly unusual circumstances.” Those inmates do not receive a projected FSA release date. To be considered at all, they must show at least three years of clear conduct and complete at least one residential evidence-based program, among other requirements, and the warden must consult the regional director before approving a transfer.
What Programs Count
The BOP assigns programs based on each inmate’s criminogenic needs—the risk factors most strongly linked to their likelihood of reoffending. Educational programs qualify, including GED completion, adult literacy, and college coursework. Vocational training in fields like carpentry, welding, coding, and commercial driving qualifies when it leads to a recognized credential.
Cognitive behavioral therapy, substance abuse treatment, and mental health programming require consistent attendance and demonstrated engagement, not just showing up. Faith-based programs and life-skills workshops also count, though availability varies by facility. Prison work assignments—kitchen, maintenance, laundry—count as productive activities when performance is satisfactory. BOP policy sets the standard work day at a minimum of seven hours.7Federal Bureau of Prisons. Inmate Work and Performance Pay Losing a work assignment to a disciplinary infraction interrupts credit accumulation.
Pre-Sentence Jail Credit
Time spent in local jail before sentencing counts toward the federal prison term, and overlooking it is one of the most common calculation errors. Under 18 U.S.C. § 3585(b), a defendant receives credit for any time spent in official detention before the sentence begins, as long as that time has not already been applied to another sentence.8Office of the Law Revision Counsel. 18 USC 3585 – Calculation of a Term of Imprisonment That covers detention for the offense that led to the sentence and detention for any charge arising after that offense was committed.
The BOP, not the sentencing court, calculates this credit after the inmate arrives at the designated facility. Errors are common when someone was held on multiple charges across different jurisdictions. If the jail credit on the sentence computation sheet looks wrong, that’s one of the most productive things to challenge.
How Credits Translate to an Earlier Release
Good conduct time comes directly off the back end of the sentence. FTCs operate differently. Once an inmate has accumulated enough credits, the BOP can apply them “in an amount that is equal to the remainder of the inmate’s imposed term of imprisonment” to place the person in prerelease custody—a Residential Reentry Center (halfway house) or home confinement.9Federal Bureau of Prisons. First Step Act – Frequently Asked Questions
The BOP Director can also transfer an eligible inmate to begin supervised release up to 12 months earlier than the projected release date based on accumulated credits.9Federal Bureau of Prisons. First Step Act – Frequently Asked Questions For inmates ineligible for FTCs because of their conviction, the home confinement window is far narrower: the shorter of 10% of the sentence or six months.
In practical terms, an FTC-eligible inmate serving an 8-year sentence who holds a low PATTERN score and completes programming consistently can finish the final year or more at home. An inmate on the same sentence who is disqualified from FTCs gets, at most, six months of home confinement.
How Credits Are Lost
Credits are not permanent. Disciplinary infractions can wipe out months or years of accumulated time, and the loss scales with the severity of the violation. Federal regulations group infractions into four severity levels, from greatest severity offenses like assault with a weapon or escape, which cost at least 41 days or 75% of available good conduct time for the period, down to low severity rule violations, which cost smaller percentages that escalate for repeat offenses.10GovInfo. 28 CFR Part 541 – Inmate Discipline and Special Housing Units
Before credits can be forfeited, the Supreme Court’s decision in Wolff v. McDonnell requires minimum due process: written notice of the charges at least 24 hours before the hearing, a written statement of the evidence relied on, and the opportunity to call witnesses and present evidence where facility safety allows.11Justia US Supreme Court. Wolff v. McDonnell, 418 US 539 (1974) Inmates do not have the right to an attorney or to cross-examine witnesses at these hearings.
Getting Credits Back
Restoration of lost FTCs is possible but not automatic. The inmate must first maintain clear conduct through two consecutive risk and needs assessments. After that, they can request restoration during a regularly scheduled program review using BOP Form BP-A1156. The unit team recommends, the Discipline Hearing Officer reviews, and the warden decides. That authority cannot be delegated below the associate warden level.6Federal Bureau of Prisons. First Step Act of 2018 – Time Credits Procedures for Implementation of 18 USC 3632(d)(4) If the request is denied, the inmate can reapply after six months, provided the record stays clean.
Good conduct time is harder to recover. The statute says credit that has not been earned “may not later be granted.”1Office of the Law Revision Counsel. 18 USC 3624 – Credit Toward Service of Sentence for Satisfactory Behavior Lost GCT is lost.
Fixing a Credit Calculation Error
Calculation errors happen. Jail credit that never got applied, programming hours that never got recorded, good conduct time withheld without documentation—any of these can add months to someone’s incarceration. There is a path to correct them, but it has strict deadlines.
The Administrative Remedy Process
Before going to court, an inmate must exhaust the BOP’s internal grievance system. It has three levels:
- Institution level (BP-9): filed within 20 calendar days of the triggering event, directed to the warden. Informal resolution with staff must usually be attempted first.
- Regional appeal (BP-10): filed within 20 calendar days of the warden’s response, directed to the regional director.
- Central office appeal (BP-11): filed within 30 calendar days of the regional director’s response, directed to the BOP General Counsel.
Each submission must address a single issue or closely related issues. Bundling unrelated complaints gets the form rejected. Missing a deadline at any level can derail the entire process.
Federal Court Review
If administrative remedies don’t resolve the problem, the next step is a federal habeas corpus petition under 28 U.S.C. § 2241. That provision is the right vehicle for challenging how a sentence is being executed, including credit miscalculations, wrongful withholding of good-time credits, and unlawfully delayed release dates.13Office of the Law Revision Counsel. 28 USC 2241 – Power to Grant Writ It is different from a § 2255 motion, which challenges the legality of the sentence itself. The filing fee is $5, and inmates who can’t afford it can apply to proceed without paying.
Courts dismiss § 2241 petitions when the inmate has not completed all three levels of administrative remedy first. Many challenges fail there—not on the merits, but because someone skipped a step or missed a filing window months earlier.