The Bureau operates institutions at five different security levels in order to confine offenders in an appropriate manner. Security levels are based on such features as the presence of external patrols, towers, security barriers, or detection devices; the type of housing within the institution; internal security features; and the staff-to-inmate ratio. Each facility is designated as either minimum, low, medium, high, or administrative.
Minimum security institutions, also known as Federal Prison Camps (FPCs), typically have dormitory housing, a relatively low staff-to-inmate ratio, and limited or no perimeter fencing. These institutions are work- and program-oriented; and many are located adjacent to larger institutions or on military bases, where inmates help serve the labor needs of the larger institution or base.
Low security Federal Correctional Institutions (FCIs) have double-fenced perimeters, mostly dormitory or cubicle housing, and strong work and program components. The staff-to-inmate ratio in these institutions is higher than in minimum security facilities.
Medium security FCIs (and USPs designated to house medium security inmates) have strengthened perimeters (often double fences with electronic detection systems), mostly cell-type housing, a wide variety of work and treatment programs, an even higher staff-to-inmate ratio than low security FCIs, and even greater internal controls.
High security institutions, also known as United States Penitentiaries (USPs), have highly-secured perimeters (featuring walls or reinforced fences), multiple- and single-occupant cell housing, the highest staff-to-inmate ratio, and close control of inmate movement.
A number of BOP institutions belong to Federal Correctional Complexes (FCCs). At FCCs, institutions with different missions and security levels are located in close proximity to one another. FCCs increase efficiency through the sharing of services, enable staff to gain experience at institutions of many security levels, and enhance emergency preparedness by having additional resources within close proximity. Inmates at a FCC can be moved within the Complex which reduces the need to be moved geographically within the BOP.