The sample reflected a cross section of the national population, grouped into 49 geographical areas. The 1,422 programs included in the final analysis represented 9,157 agencies nationwide. Of these programs, 101 provided primary prevention services related to substance abuse. Another 1,560 programs provided secondary intervention consisting of counseling and other therapy aimed at other problems, for which substance abuse was viewed as one symptom. An additional 71 programs provided tertiary services focusing on treatment of substance abuse as the focal problem. The distribution of the numbers suggests that substance abuse among youth is seen mainly as a symptom of other difficulties. Agencies were analyzed in terms of funding, staffing patterns and training, location, client, characteristics, and services provided. The primary, secondary, and tertiary agencies differed significantly in many respects. The prevalance of secondary agencies showed that youths who are abusing substances are most likely to receive help through a program whose services are not specifically designed to address problems of substance abuse. More attention should focus on training staff in these programs to identify and intervene with youth who are abusing alcohol or drugs. Data tables.