U.S. federal prison

The Federal Bureau of Prisons classifies prisons into several categories:

This list does not include military prisons, state prisons, jails, or prisons operated under contract with local governments. It also does not include detention centers and facilities and processing centers run by Immigration and Customs Enforcement (ICE).

Most United States Penitentiaries (USPs) are high-security facilities, which have highly secured perimeters with walls or reinforced fences, multiple and single-occupant cell housing, the highest staff-to-inmate ratio, and close control of inmate movement. The most notable facility in the federal prison system is Florence ADX, the federal supermax prison in Florence, Colorado, which holds inmates who are considered the most dangerous and in need of the tightest controls. USP Atlanta, USP Leavenworth, USP Lompoc, and USP Marion are medium-security facilities. USP Hazelton is in the process of adding a medium-security facility to its existing high-security unit. USP Marion contains a highly restrictive Communication Management Unit, which holds inmates under stricter controls. Many USPs include minimum-security satellite camps on the same property and under the same administration as the higher-security unit(s).

† Includes female inmates

Federal Correctional Institutions (FCIs) are medium- and low-security facilities, which have strengthened perimeters (often double fences with electronic detection systems), mostly cell-type housing, a wide variety of work and treatment programs, as well as a higher staff-to-inmate ratio and greater internal controls than low-security FCIs. FCI Terre Haute contains a more restrictive section designated as a Communication Management Unit for inmates considered high-security risks.

† Includes female inmates
†† Female-only facility

In August 2016, Justice Department officials announced that the FBOP would be phasing out its use of contracted facilities, on the grounds that private prisons provided less safe and less effective services with no substantial cost savings. The agency expects to allow current contracts on its thirteen remaining private facilities to expire. Those facilities are:

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