The Federal Bureau of Prisons operates 122 correctional institutions across the United States, holding roughly 153,500 inmates as of early 2026.1Federal Bureau of Prisons. BOP Our Locations That count covers the prisons themselves, not the halfway houses, regional offices, or training centers that surround them. The number moves as facilities open, close, or change missions, so 122 is a current snapshot rather than a fixed figure.
What the 122 Institutions Include
The BOP sorts its 122 institutions into four main security levels, plus a set of administrative facilities built around specific missions rather than a single risk tier. Security level is the practical dividing line: it decides whether an inmate sleeps in a dormitory or a cell, whether the perimeter is a fence, a double fence, or a wall, and how closely staff track movement inside.
The population is spread unevenly across those levels.2Federal Bureau of Prisons. BOP Statistics: Prison Security Levels
- Minimum security, called Federal Prison Camps, use dormitory housing with limited or no perimeter fencing and hold about 14.8% of inmates.
- Low security Federal Correctional Institutions use double fences, dormitory or cubicle housing, and a higher staff-to-inmate ratio than camps. They hold the largest share at 36.2%.
- Medium security Federal Correctional Institutions add cell-type housing, strengthened perimeters, and tighter internal controls, holding 32.7%.
- High security United States Penitentiaries use walls or reinforced fences, single- or multi-occupant cells, and close control of all movement. They hold 12.1%.
Another 4.2% of inmates are unclassified, meaning they have not yet been assigned a security level.3Federal Bureau of Prisons. Federal Bureau of Prisons – Federal Prisons
ADX Florence, the Only Supermax
One facility sits above the standard high-security tier. USP Florence ADMAX in Colorado, known as ADX Florence, is the only administrative-maximum prison in the federal system and holds roughly 407 inmates.4Federal Bureau of Prisons. USP Florence ADMAX It houses inmates whose behavior at other high-security facilities made them too dangerous to manage in a conventional setting. The BOP places ADX in its “administrative security” category, which covers facilities with special missions rather than a single security level.
Administrative and Specialized Facilities
Not every federal prison fits the minimum-through-high ladder. Several types of administrative facilities exist to do a specific job regardless of the inmates’ classifications.3Federal Bureau of Prisons. Federal Bureau of Prisons – Federal Prisons
Pretrial Detention Centers
Metropolitan Detention Centers and Metropolitan Correctional Centers primarily hold people who have not been sentenced. They sit in or near major cities so that inmates can be moved to federal courthouses for hearings and trial. Because pretrial detainees range from white-collar defendants to people facing serious violent charges, these facilities have to accommodate a wide range of security needs under one roof.
Medical Referral Centers
Seven medical referral centers provide advanced care for inmates with chronic illnesses, serious injuries, or acute conditions that standard institutions cannot treat.5Federal Bureau of Prisons. Medical Care They function as hospitals inside the prison system, staffed by medical professionals alongside correctional officers, and receive transfers from other facilities.
Federal Transfer Centers
Federal Transfer Centers act as transit hubs for inmates moving between institutions. The largest is FTC Oklahoma City, at Will Rogers World Airport, which processes inmates around the clock five days a week and temporarily houses about 1,500 people at a time with an average stay of roughly 30 days.6Federal Bureau of Prisons. FTC Oklahoma City Has One-of-a-Kind Mission It coordinates with the U.S. Marshals Service to route inmates to their designated facilities.
What Sits Outside the 122
The 122 figure does not include halfway houses. The BOP contracts with 155 residential reentry centers where inmates nearing release can look for work, reconnect with family, and adjust to life outside a locked facility.7Federal Bureau of Prisons. Residential Reentry Management Centers8Federal Bureau of Prisons. Reentry Programs These are run by private contractors and overseen by 22 BOP residential reentry management offices. Placement is not automatic; the BOP decides eligibility based on factors like remaining sentence length and institutional behavior.
The population figure itself also spans more than the 122 institutions. As of March 2026, 138,808 of the 153,535 federal inmates were in BOP-operated facilities, and 14,727 were in other settings such as contracted local jails or community-based placements.9Federal Bureau of Prisons. Population Statistics The same snapshot showed zero inmates in privately managed prisons.
Why the Number Changes
In late 2024, the BOP announced plans to close seven facilities, including the federal correctional institution in Dublin, California, along with several minimum-security camps and satellite camps. The closures reflected a mix of declining populations at those sites, infrastructure problems, and budget pressure. When a facility closes, inmates are transferred elsewhere in the system and staff are reassigned or offered positions at nearby BOP sites.
The status of private contract prisons has moved with each administration. A 2021 executive order directed the Department of Justice to stop renewing contracts with privately operated criminal detention facilities. That order was reversed in January 2025. Even so, the BOP reported zero inmates in privately managed facilities as of March 2026.9Federal Bureau of Prisons. Population Statistics For now, all 122 institutions are government-operated.