This report was produced as part of the Strong Science for Strong Practice: Linking Research to Drug Treatment in the Criminal Justice System project, funded by the National Institute on Drug Abuse. The project involved collecting and reviewing information on the extent of drug treatment need in correctional settings, how this need is identified and addressed, how the amount and quality of treatment can be improved, and how research can be targeted to assist with the implementation of science-based drug treatment practice. In addition to conducting a comprehensive literature review, the Strong Science for Strong Practice project included interviews with and a meeting of knowledgeable practitioners and researchers. This report provides a summary of the comprehensive literature review.