While more than half of individuals incarcerated in U.S. jails and prisons meet the diagnostic criteria for a substance use disorder, little is known about their misuse of prescription drugs. In this study, Authority researchers, in collaboration with WestCare Foundation Illinois, surveyed 573 state prisoners on prescription drug use to examine prevalence, accessibility, motivation for use, and effects. Forty-six percent of the sample reported using prescription drugs to get high and 20 percent used prescription drugs daily in the year before their incarceration.