Health systems have not implemented Screening, Brief Intervention and Referral to Treatment (SBIRT) for adolescents despite research demonstrating its effectiveness. Based on prior research that identified barriers to AOD screening for adolescents in pediatric Primary Care (PC) and a pilot study that found SBIRT was feasible, well-received and promoted referrals to and initiation of specialty treatment, the current research application proposes to randomize 45 Primary Care Physicians (PCPs) in the pediatrics clinic of a medical center within a large, managed care health system, Kaiser Permanente Northern California, to three arms - 1) Usual Care; 2) SBIRT delivered by PCPs; and 3) SBIRT delivered by Behavioral Medicine Specialists (BMS). The study objective is to compare the implementation, effectiveness and cost-effectiveness of SBIRT for adolescents in PC in the three study arms. Patients will complete evidence-based screening and AOD assessment measures which have been embedded in the health plan's electronic medical record (EMR). A mixed model will be used to compare implementation outcomes (rates of screening and identification, brief intervention, referral to Chemical Dependency treatment and treatment initiation), and effectiveness (patient outcomes of AOD use and abstinence) at 12 months. The model accounts for the intra-class correlations across patients within providers. Cost-effectiveness relative to implementation and patient outcomes will be examined. Barriers and facilitators of implementation, and feasibility via qualitative interviews with clinicians and administrators will be examined as well. The study is significant in that it examines issues that must be addressed to spur widespread adaptation of SBIRT. The proposed interventions are highly feasible in the current environment of health reform due to increased resources and training to Federally Qualified Health Centers and private health plans. It is innovative in using the EMR to change clinical practice and systematically integrate AOD in PC, and as a platform for collecting research data.