Research on effective rehabilitation of drug-involved offenders has advanced considerably in recent years. Yet policies and practices remain rooted in sentiments from decades past when authorities did not know how to supervise drug offenders closely, apply effective behavioral consequences, or treat the disease of addiction. This article reviews evidence-based practices in sentencing, supervision, treatment, and reentry for drug-involved offenders, drawing on painful lessons from past failed policies. Recommendations are offered at each stage in the justice process for incorporating evidence-based principles into sentencing laws, correctional practices, and treatment interventions.