Contingency management (CM) treatments evolved from basic behavioral research demonstrating that reinforcing behavior increases the probability it will occur in the future. CM is a structured behavioral therapy that involves: (1) frequently monitoring an objectively verifiable target behavior, (2) reinforcing the behavior each time it occurs using tangible reinforcers, and (3) withholding reinforcement when the target behavior is not met. Often, the target behavior is drug abstinence, but other behaviors such as attendance at treatment, medication adherence, and engagement in treatment-related activities, can also be reinforced. Patients earn reinforcement contingent upon submission of drug negative urine samples or treatment attendance. The two most common CM delivery systems are Prize-based (fishbowl) CM and Voucher CM. In Prize-based CM, patients earn draws from a fishbowl with the chance to win prizes ranging from $1 to $100 in value. In Voucher CM, patients earn set dollar amounts in vouchers; earned vouchers are exchangeable for goods and services. In both Prize- and Voucher-CM, reinforcers typically increase with sustained demonstration of the target behavior. Usually, CM treatments are in effect for 8-24 weeks, and CM is often provided as an adjunct to other treatment. It can be integrated with virtually any form of therapy, including eclectic/standard group treatment, 12-step therapy, cognitive-behavioral therapy, community reinforcement approach therapy, motivational enhancement therapy, and others. If abstinence is reinforced, the best outcomes of CM are generally achieved if abstinence from a single drug or single drug class (e.g., stimulants) is reinforced (as opposed to requiring abstinence from multiple substances concurrently to receive reinforcement), if urine testing monitoring is conducted at least twice weekly, if onsite (as opposed to offsite) testing procedures are used to allow for immediate results and reinforcement, and if reinforcement magnitude is consistent with evidence-based protocols.