What Is BOP Custody and How Does Federal Prison Work?

BOP custody is the legal status of anyone held under the authority of the Federal Bureau of Prisons, whether that means a federal prison, a halfway house, or home confinement. The Bureau operates 122 institutions and holds roughly 139,000 people at any given time. Your custody status controls where you live, what programs you can join, how much of your sentence you actually serve, and how much day-to-day freedom you have. Most of what happens inside is shaped by a scoring system and a set of incentives you can influence, not by the judge who sentenced you.

Who Is in BOP Custody

Federal law puts every federal prison under the Attorney General, who delegates operations to the Bureau of Prisons.¹ The BOP manages every federal correctional institution in the country, from minimum-security camps to high-security penitentiaries.² This is a separate system from state prisons and county jails. If you’re charged with or convicted of a federal crime, you fall under this jurisdiction.

You enter BOP custody after a federal judge issues either a detention order before trial or a commitment order after conviction. From that point, the BOP handles housing, medical care, work assignments, and programs. Pretrial detainees who haven’t been convicted often share facilities with sentenced people, though the legal basis for holding each group differs. Time you spent in a local jail or federal detention before sentencing generally counts toward your sentence.³

Where You’ll Be Housed

The BOP assigns every institution one of five security levels based on physical features like fencing, housing type, detection systems, and staff-to-inmate ratio.⁴ The BOP itself decides which one you go to, and that decision is not reviewable by any court.⁵

Minimum security (Federal Prison Camps): dormitory housing with little or no perimeter fencing, the lowest staff-to-inmate ratios, and an emphasis on work and programming.
Low security: double-fenced perimeters, dormitory or cubicle housing, more staff presence, but relatively open movement inside.
Medium security: reinforced fencing, electronic detection, cell-based housing, and tighter internal controls.
High security (U.S. Penitentiaries): walls or reinforced fencing, cells, and the highest staff-to-inmate ratios. These house people serving long sentences or those the BOP treats as the greatest security risk.
Administrative facilities: institutions with special missions, including Federal Medical Centers for serious health conditions and metropolitan detention centers for pretrial holds. They can house people at any security level.

How the BOP Assigns Your Security Level

When you enter the system, the BOP’s Designation and Sentence Computation Center runs your case through a point-based scoring system on the BP-337 form. The total determines your security level. For men, 0 to 11 points is minimum, 12 to 15 is low, 16 to 23 is medium, and 24 or more is high. The scale is different for women: 0 to 15 is minimum, 16 to 30 is low, and 31 or more is high.⁶

The factors feeding your total include the severity of your offense (0 to 7), criminal history (0 to 10), history of violence (0 to 7, with the highest score for serious violence within the last five years), any escape history, outstanding detainers from other jurisdictions, age (up to 8 points if you’re 24 or younger; 0 if you’re 55 or older), education (0 with a verified high school diploma or GED; 2 without one and not enrolled), and recent substance abuse.

On top of the raw score, the BOP applies Public Safety Factors that can override the numbers. A history of juvenile violence, involvement in a prison disturbance, or a serious escape can push you into a higher-security facility no matter what the points say.⁶

Placement Near Home

Federal law directs the BOP to place you as close as possible to your primary residence, ideally within 500 driving miles.⁵ In practice, bed space, your security level, medical needs, and sentencing court recommendations often take priority. A DOJ Inspector General audit found the BOP has historically struggled to meet the 500-mile requirement.⁷

Reclassification Over Time

Your security score isn’t fixed. The BOP reviews custody periodically using the BP-338 form, comparing your original designation against your behavior since the last review. Good conduct, program completion, and a nearing release date can lower your score. Disciplinary infractions can raise it.⁶

How You Can Shorten Your Time

Two separate mechanisms can move your release date earlier. They stack, and both reward the same behavior.

Good Conduct Time

If you’re serving more than one year, you can earn up to 54 days off your sentence per year of the term the court imposed, as long as the BOP finds you’ve shown exemplary compliance with facility rules.⁸ Credit is calculated against the sentence the judge imposed, not time served. On a 10-year sentence, that potentially adds up to 540 days. The BOP also considers whether you’re making progress toward a GED or high school diploma when it awards credit. Credit not earned in a given year can never be granted later, so a bad year early on leaves a permanent gap. People serving life sentences are excluded.

First Step Act Earned Time Credits

Participating in approved programs or productive activities earns 10 days of time credit for every 30 days of participation.⁹ If the BOP’s risk assessment rates you as minimum or low risk across two consecutive evaluations, that jumps to 15 days per 30 days of programming. These credits apply toward earlier transfer to prerelease custody (halfway house or home confinement) or to supervised release.

The risk score comes from a tool called PATTERN (Prisoner Assessment Tool Targeting Estimated Risk and Needs). It weighs static factors like age, criminal history, and violence history, and dynamic factors you can influence: education status, drug treatment completion, disciplinary record over the past 10 years, time since your last infraction, programs completed, and participation in the Inmate Financial Responsibility Program.¹⁰ Refusing IFRP counts against your score.

Not everyone qualifies. A long list of offenses disqualifies you from earning FSA time credits, including terrorism-related crimes, serious violent offenses, sex offenses, offenses involving minors, espionage, and certain drug crimes.¹¹ People under a final order of deportation cannot apply earned credits toward prerelease custody either.⁹ Disqualified individuals can still participate in programming, but the credits won’t accelerate release.

How You Can Lose Time

The BOP sorts rule violations into three tiers: greatest, high, and moderate severity. Greatest-severity acts include sexual assault, escape, and possessing a cell phone. High-severity acts include stalking, possessing stolen property, and tattooing.¹²

For a greatest-severity violation, the BOP can forfeit between 50% and 75% (27 to 41 days) of the good conduct time you were eligible to earn that year, and that sanction cannot be suspended.¹³ Up to 41 days of earned FSA time credits can be forfeited per violation. Other sanctions include up to 12 months in disciplinary segregation, loss of visiting, telephone, commissary, and recreation privileges, and monetary fines. Warnings and reprimands are no longer used as formal sanctions. Once you’re written up, the process moves directly to real consequences, and months of accumulated credit can vanish in a single incident.

The Last Stretch: Community-Based Custody

Custody doesn’t necessarily end at the prison fence. Federal law directs the BOP to spend up to the final 12 months of a sentence preparing people for reentry.⁸ That takes two main forms.

Residential Reentry Centers, commonly called halfway houses, house you at the facility with a curfew and an expectation that you find work. Staff monitor your schedule, run drug tests, and verify your whereabouts. You’re still in BOP custody and subject to BOP rules. Placement can run up to 12 months before your release date.

Home confinement lets you serve the tail end of your sentence at your own residence, but the window is narrower: the shorter of six months or 10% of your total sentence.⁸ On a three-year sentence, that’s roughly 3.6 months. On a 10-year sentence, the six-month cap kicks in. FSA time credits can move you into either form of prerelease custody earlier than the standard timeline allows.⁹

Either way, monitoring comes with the arrangement. GPS ankle devices provide continuous tracking and alert officers when you enter or leave designated areas. Radio frequency transmitters worn on the ankle communicate with a receiver in your home and report when you leave signal range. Lower-risk cases may use voice recognition phone calls or a mobile app that verifies location through facial recognition or fingerprint.¹⁴ GPS and radio frequency are 24/7; phone and app checks are periodic. Movement is limited to approved activities like work, medical appointments, and religious services, and unauthorized movement can send you back to a secure facility.

Money You Owe While Inside

If you owe court-ordered fines, restitution, or the mandatory special assessment attached to every federal conviction, the BOP expects payment through the Inmate Financial Responsibility Program. Your unit team reviews your obligations at your initial classification and sets a payment plan. Obligations are paid in a set priority order: special assessments first, then restitution, then fines and court costs, then state or local obligations.¹⁵

For most inmates with regular work assignments, the minimum payment is $25 per quarter. If you work in UNICOR at grades 1 through 4, you’re expected to put at least 50% of your monthly pay toward your obligations, with $75 per month excluded from the calculation for personal spending. Participation is technically voluntary, but refusing counts against your PATTERN score and can limit access to preferred housing and programs.¹⁰

The BOP charges a $2 copay for health care visits you request. It doesn’t apply to emergency care, follow-up visits scheduled by medical staff, or chronic care.¹⁶ Commissary spending is capped at $360 per month for regular items, though stamps, phone credits, and over-the-counter medications may fall outside that cap. As of January 2025, inmates participating in First Step Act programming receive 300 free phone minutes per month; those who opt out pay for their own phone and video time.¹⁷

Challenging a BOP Decision

When you disagree with a BOP decision (a disciplinary outcome, your classification, or another aspect of confinement), the administrative remedy program is the formal channel. You have to exhaust it before any federal court will hear a legal challenge, so skipping steps isn’t an option.

The process runs in four stages: informal resolution with staff, a written request to the warden on a BP-9 within 20 calendar days of the event, an appeal to the Regional Director on a BP-10 within 20 calendar days of denial, and a final appeal to the General Counsel at the Central Office on a BP-11 within 30 calendar days.¹⁸ Miss a deadline and you’ve likely lost the ability to challenge the decision in court. Keep copies of everything you file; courts expect you to prove you completed each step.

1
Office of the Law Revision Counsel. 18 U.S.C. 4001 – Limitation on Detention; Control of Prisons
2
Office of the Law Revision Counsel. 18 U.S.C. 4042 – Duties of Bureau of Prisons
3
Office of the Law Revision Counsel. 18 U.S.C. 3585 – Calculation of a Term of Imprisonment
4
Federal Bureau of Prisons. About Our Facilities
5
Office of the Law Revision Counsel. 18 U.S.C. 3621 – Imprisonment of a Convicted Person
6
Federal Bureau of Prisons. Inmate Security Designation and Custody Classification
7
U.S. Department of Justice Office of the Inspector General. Audit of the Federal Bureau of Prisons Efforts to Place Inmates Close to Home
8
Office of the Law Revision Counsel. 18 U.S.C. 3624 – Release of a Prisoner
9
Office of the Law Revision Counsel. 18 U.S.C. 3632 – Development of Risk and Needs Assessment System
10
Federal Bureau of Prisons. Male PATTERN Risk Scoring
11
Federal Bureau of Prisons. Good Time Disqualifying Offenses
12
Federal Bureau of Prisons. Inmate Discipline Program
13
eCFR. 28 CFR 541.3 – Prohibited Acts and Available Sanctions
14
United States Courts. Use of Location Monitoring in the Field
15
Federal Bureau of Prisons. Inmate Financial Responsibility Program
16
Federal Bureau of Prisons. Inmate Copayment Program
17
Federal Bureau of Prisons. FBOP Updates to Phone Call Policies and Time Credit System
18
eCFR. 28 CFR Part 542 – Administrative Remedy