The authors present a cost-benefit analysis of a Juvenile Breaking the Cycle (JBTC) program in Oregon designed to provide juvenile justice system monitoring and coordinated treatment and services to youth who are assessed as at high risk for recidivism and substance use. Detailed cost analyses are presented for youth in the JBTC program and a comparison group. Multivariate models for all costs combined indicate that the costs per JBTC youth are much higher than for the comparison group 6 to 12 months after intake. Twelve to 18 months after intake, the difference in juvenile justice costs between the two groups is negligible. These findings suggest that decision makers should not expect any additional case management and treatment costs to be offset immediately by reductions in juvenile justice costs. However, evidence suggests that juvenile justice costs may eventually be at least equivalent to usual care. (Contains 4 tables and 1 figure.)