For the proposed study, 204 adolescents meeting diagnostic criteria for substance abuse or dependence will be randomized to either the Contingency Management-Family Engagement (CM-FAM) or Treatment as Usual (TAU) conditions. A multimethod, multirespondent approach will be used to track clinical outcomes at 3, 6, 9, 12, and 18 months post recruitment. Clinical level outcomes pertain to youth substance use, criminal behavior, mental health functioning, and key mediators of serious antisocial behavior in adolescents (e.g., self-control, parental supervision, association with deviant peers). In addition, the incremental cost of CM-FAM will be determined for use in cost effectiveness analyses.