Treatment Foster Care Oregon (TFCO) is an alternative to congregate care, for youth involved in the juvenile justice and/or child welfare systems. Though demonstrated as clinically-and cost-effective across multiple rigorous trials, the long-term cost benefit of TFCO has not been considered. This study follows n = 166 females from adolescence to young adulthood, who were involved in both systems and referred for out-of-home-care. Records of arrest, court, incarceration (juvenile, jail, and prison), monitoring (parole and probation) and child-welfare services were included in a long-term cost-benefit analysis. Outcomes highlight ongoing benefit of the TFCO intervention, nearly 10 years post-intervention.