The authors note that national surveys indicate that marijuana is the illicit drug of choice among adolescents, the authors indicate that basic research assessing the cost of adolescent substance abuse treatment programs is essentially nonexistent. After arguing the importance of gauging the cost effectiveness of the CYT program, the authors begin by briefly describing the five manual-guided motivational enhancement therapy, cognitive behavior therapy, family support network, adolescent community reinforcement, and multidimensional family therapy approach treatment models that comprise the CYT program. Using the Drug Abuse Treatment Cost Analysis Program (DATCAP), the authors assessed the economic costs of each of the site-specific treatment programs. They found that the average economic costs of the five different outpatient treatment models ranged from $837 to $3,334 per treatment term. Economic costs for the different programs varied according to the hours of treatment, treatment retention rates, the cost of living in the different geographic areas, the number of staff members associated with the treatment program, and caseload variations. The authors conclude that the CYT intervention programs with the highest costs do provide more services, indicating that CYT programming costs appear to be justified, but additional research is needed in order to fully determine the cost-effectiveness of the CYT program. Tables, references