State Prison Overcrowding and Capacity Data
Original story by Ryan Spohn, Nebraska Center for Justice Research | Original visualization by Mike Maciag
Story and visualizations updated by Melanie Kiper, 8/17/2020
Prison overcrowding has become a growing social problem in the United States as state incarceration rates increased from the 1970s, peaking in 2008. Although some states have experienced recent decreases in prison overcrowding, often as a result of “justice reinvestment” initiatives and reform efforts, overcrowding remains a significant problem in many state correctional systems. We use data from Table 17 of the Bureau of Justice Statistic’s Prisoners in 2018 report to examine rates of prison overcrowding across states.
Our analysis compares rates of operational capacity across states, indicating that Midwestern states such as Nebraska and Iowa lead the nation in rates of prison overcrowding compared to their rated operational capacity. In comparison to Nebraska’s nation-leading prison overcrowding rate of 130.4%, Rhode Island reported by far the lowest level of overcrowding at 68.4%, followed by Tennessee at 74.6%. It is worth noting that Nebraska and other select states utilize their own definitions that differ from the federal definition for capacity, so statistics are not entirely comparable across states.
Examinations of prison overcrowding can further be challenging as multiple measures of capacity exist. For example, “design capacity” is the number of inmates a facility can hold according to the architect or planner and represents the lowest capacity estimate, but this measure is not provided by all states. Looking at this latter measure, Alabama leads all states at 168.2% of design capacity, whereas Nebraska comes in second at 158.0%. One additional caveat of state incarceration crowding measures is that they reflect the entire state correctional system, whereas individual facilities within the system may face rates of crowding that are substantially over or under the state mean rate.
Note: Alaska, Connecticut and Ohio did not report 2018 operational capacity data.
Design capacity: Number of inmates who can be held based on facility's architect or planner.
Operational capacity: Number of inmates who can be held based on staffing and services.
Rated capacity: Refers to inmates or beds a facility can accommodate, set be a rating official.
Prison population: Prisoners in custody of a prison system, "regardless of sentence length or the authority with jurisdiction over the prisoner."
- Numbers exclude prisoners held in local jails, other states, or private facilities, unless otherwise noted.
- Alabama, Delaware, Missouri, Nebraska, South Dakota, and Texas use a definition of capacity different than the federal BJS definition. See jurisdiction notes on BJS website.
- Alaska's capacity figures excludes non-traditional confinement, such as halfway houses and electronic monitoring.
- Arizona, Georgia, Idaho, Pennsylvania and South Dakota numbers also reflect private correctional facilities.
- Illinois's rated capacity is under revision, and these numbers are the ceiling operational capacity. Numbers are not comparable to prior reports.
- Indiana's numbers include state-owned facilities staffed with private sector employees.
- Maryland's operational capacity may include some pre-trail detainee beds exluded from the custody county.
- Mississippi's capacity and custody totals include local facilities.
- New Hampshire and Oregon did not submit 2018 NPS data on custody or capacity. Custody countwa s imputed and capacities were assumed to have not changed from the most recent year the state submitted NPS data.