Survey of Prison Inmates, United States, 2016

The SPI sample was selected from a universe of 2,001 unique prisons (1,808 state and 193 federal) that were either enumerated in the 2012 Census of State and Federal Correctional Facilities or had opened between the completion of the census and July 2014. The target population for the 2016 SPI was male and female prisoners age 18 or older who were held in a state prison or were serving a sentence to federal prison in the U.S. during 2016.