Clinical research trials demonstrate the efficacy of contingency management procedures in treating substance use disorders. Usually, reinforcement, in the form of vouchers exchangeable for retail goods and services, is provided for drug abstinence in patients treated in psychosocial or methadone maintenance clinics. Recently, the types of reinforcers have been adapted to include lower cost alternatives, and reinforcement is being expanded to alter other target behaviors such as attendance at treatment, adherence to treatment goals, and compliance with medication. This chapter provides an overview of the populations and behaviors to which contingency management approaches have been applied. It also reviews design features that appear critical in the successful adaptation of the techniques. In addition, areas for future research are described.