OBJECTIVE: This article describes drinking patterns and examines the prevalence of heavy drinking and alcohol problems, and their association with other behavioral and social problems within the membership of a health maintenance organization, a setting in which increasing numbers of Americans receive services. METHOD: The sample is representative of the stably insured membership of the Northern California Region of Kaiser Permanente Medical Care Program; i.e., those who have been insured continuously under that plan for 30 months or longer. A telephone survey of the adult membership (N = 10,292) was conducted between June 1994 and February 1996. RESULTS: As in other studies, health and mental health status and smoking were related to drinking levels, with symptoms higher for those in the heaviest drinking group. However, in contrast to studies of those using medical services, demographic characteristics (e.g., young age) were not associated with heavy drinking in this population. When controlling for drug use and drinking, however, women and those reporting any mental health symptom were more likely to report alcohol problems. CONCLUSIONS: Findings suggest that in private managed care populations, particular behavioral indicators may be more important than demographic characteristics in screening for problem drinkers. The identification of individuals who report a mental health symptom, who drink a large number of drinks occasionally or who report any drug use may be important in a health maintenance approach to prevention and case finding.