Prisons are grouped into 5 distinct security levels in order to confine inmates. Each level may contain varying degrees of external patrols, security barriers, towers, or detection devices. The level of security is also based on such factors as the type of housing within the institution, internal security features, and staff/inmate ratio.
Minimum Security Facilities – Minimum security Federal Prison Camps have dormitory housing, a fairly low staff-to-inmate ratio, and little to no perimeter fencing.
Low Security Facilities – Low security Federal Correctional Institutions have multi-fenced perimeters, mostly dormitory or cubicle housing, and strong work and/or program parts, with the staff/inmate ratio being higher than in minimum security facilities.
Medium Security Facilities – Medium security Federal Correctional Institutions (and also United States Penitentiaries for medium security inmates) have strengthened perimeters (multi-fence with electronic recognition systems), greater internal controls, mostly cell housing, and an even higher staff/inmate ratio than low security Federal Correctional Institutions.
High Security Facilities – High security United States Penitentiaries (USPs), contain highly secured perimeters with walls and/or reinforced fences, close monitoring of inmate movement, multiple/single inmate cell housing, and the highest staff/inmate ratio.
Administrative Facilities- Administrative institutions have special missions such as the detention of pretrial offenders, inmates with serious or chronic medical problems, and inmates that are extremely dangerous, violent, or even escape-prone. Administrative facilities are capable of holding inmates in any if the security categories.
Additional Facilities – Satellite Camps and Satellite Low Security Facilities also exist. They are usually minimum security camps that are affiliated with the core facility.