The Minnesota Sex Offender Screening Tool–Revised (MnSOST–R) is a 16-item, “actuarial” risk assessment tool initially developed for the Minnesota Department of Corrections (MDOC) to provide empirically based estimates of risk for sexual recidivism for incarcerated male sex offenders. Indices of reliability have ranged from .76 to .86 across four studies and have generally been .80 or greater. The MnSOST–R has been successfully validated in Minnesota; North Dakota; and Ontario, Canada; however, it failed to predict significantly better than chance in an Arizona study.