Objective: To review the research on economic and systemic barriers faced by adolescents needing treatment for alcohol and drug problems, particularly those with co-occurring conditions. Method: We reviewed the literature on adolescent access to alcohol and drug services, including early intervention, and integrated and specialty mental health treatment for those with co-occurring disorders, examining the role of health care systems, public policy (health reform), treatment financing and reimbursement systems (public and private), implementation of evidence-based practices, confidentiality practices, and treatment costs and cost/benefits. Results: Barriers to treatment, particularly integrated treatment, are largely rooted in our organizationally fragmented health care system, which encompasses public and private, carved-out and integrated systems, and different funding mechanisms (Medicaid versus block grants versus private insurance that include "high deductible" plans and other cost controls.) In both systems, carved-out programs de-link services from other mental health and general health care. Barriers are also rooted in disciplinary differences and weak clinical linkages between psychiatry, primary care and substance use, and in confidentiality policies that inhibit communication and coordination, while protecting patient privacy. Conclusion: In this era of health care reform, we have the opportunity to increase access for adolescents and develop new models of integrated services for those with co-occurring conditions. We discuss opportunities for improving treatment access and implementation of evidence-based practices, examine implications of health reform and parity legislation for psychiatric and substance use treatment, and comment on key unanswered questions and future research opportunities.