1974, 1979, 1986, 1991, 1997, 2004, 2016
The Survey of Prison Inmates (SPI) is a periodic, cross-sectional survey of the state and sentenced federal prison populations. Its primary objective is to produce national estimates on the state and sentenced federal prison populations across a variety of domains, including but not limited to demographic characteristics, current offense and sentence, incident characteristics, firearm possession and sources, criminal history, socioeconomic characteristics, family background, drug and alcohol use and treatment, mental and physical health and treatment, and facility programs and rule violations. From January through October 2016, data were collected through face-to-face interviews with prisoners using computer-assisted personal interviewing (CAPI).
Prior iterations of the SPI were known as the Survey of Inmates in State and Federal Correctional Facilities (SISFCF), which was renamed with the 2016 implementation. The first survey of state prisoners was fielded in 1974 and thereafter in 1979, 1986, 1991, 1997, and 2004. The first survey of federal prisoners was fielded in 1991, along with the survey of state prisoners, and since then both surveys have been conducted at the same time using the same questionnaire and administration.