The juvenile justice system serves a marginalized and vulnerable population of high-risk youth who have been convicted of committing crimes. This system uses substantial state budgets for housing, staffing, and programming for the youth offender population. As states look to reform their juvenile justice systems, one specific model they should consider implementing is the Multi-Systemic Treatment (MST) approach, an intensive residential-based intervention for chronic, violent, or substance abusing juvenile offenders, ages 12 to 18, that uses trained therapists to work in small facilities with the youth and his or her family. This study examines the Missouri Model, an MST program that was successfully implemented statewide. This paper provides a cost-benefit analysis of a proposed transformation of California’s juvenile justice system by implementing the MST model at a statewide level.