The results of these analyses show a consistent pattern. Whether residential or nonresidential, the correctional programs included in these analyses showed increases in recidivism rates unless offenders who were higher risk were targeted and provided more services for a longer period of time. Results indicated that even when some form of cognitive behavioral therapies (CBT) was provided it was not sufficient. Offenders who are higher risk must also be provided more services and kept in programming longer to have appreciable effects on outcome. Based on the findings, the following select recommendations are presented and include: (1) correctional programs need to utilize objective and standardized assessment tools to identify appropriate offenders for highly structured programs; (2) a range of services and interventions should be provided that target the specific crime-producing needs of the offenders who are higher risk; and (3) a validated risk assessment method that meaningfully differentiates between offenders who are high risk and low risk should be utilized. The risk principle states that the level of supervision and treatment should commensurate with the offender’s level of risk. The risk principle has been confirmed by research in corrections for more than a decade. This study improves on earlier attempts to assess the importance of the risk principle by analyzing data from two separate studies. Collectively, data were provided from 97 programs and a total of 13,676 individual offenders. The study examined whether programs that adhered to the risk principle by providing more services and referrals for treatment to offenders who were higher risk were more effective. It also examined whether programs that provided more services and/or supervision to offenders who were higher risk for a longer period of time were more effective. Tables, figures, notes, and references