This study examined the system-level effects of implementing a promising treatment for adolescent substance abuse in juvenile drug courts (JDCs). Six JDCs were randomized to receive training in the experimental intervention (contingency management–family engagement [CM-FAM]) or to continue their usual services (US). Participants were 104 families served by the courts, 51 therapists, and 74 JDC stakeholders (e.g., judges, prosecutors, defense attorneys). Assessments included repeated measurements of CM-FAM implementation by therapists and therapist and stakeholder perceptions of incentive-based interventions and organizational characteristics. Results revealed greater use of CM and family engagement techniques among CM-FAM relative to US therapists. In addition, therapists and stakeholders in the CM-FAM condition reported more favorable attitudes toward the use of incentives and greater improvement on several domains of organizational functioning relative to US counterparts. Taken together, these findings suggest that JDC professionals are amenable to the adoption and implementation of a treatment model that holds promise for improving youth outcomes.