Responding to urgent calls for effective interventions to address young offenders' multiple and interconnected problems, a new variant of an existing empirically-validated intervention for drug-using adolescents, Multidimensional Family Therapy (MDFT)Detention to Community (DTC) was tested in a two-site controlled trial. This article (a) outlines the rationale and protocol basics of the MDFT-DTC intervention, a program for substance-using juvenile offenders that links justice and substance abuse treatment systems to facilitate adolescents' postdetention community reintegration; (b) presents implementation outcomes, including fidelity, treatment engagement and retention rates, amount of services received, treatment satisfaction, and substance abusejuvenile justice system collaboration outcomes; and (c) details the implementation and sustainability challenges in a cross-system (substance abuse treatment and juvenile justice) adolescent intervention. Findings support the effectiveness of the MDFT-DTC intervention, and the need to develop a full implementation model in which transfer and dissemination issues could be explored more fully, and tested experimentally. (Published Abstract)