Twelve- to eighteen-year-olds enrolled in a federally qualified HMO in Central Massachusetts who had an admission to a hospital with a diagnosis of trauma or mental health problems were identified. Routine and episodic health care utilization for a 24-month period of each study case was determined and compared with the same for a comparison group matched for age, sex and length of enrollment. Although information on health habits and lifestyle was often missing from the charts, it was determined that the study cases were less likely to be in school and living with their parents and used episodic care more frequently, especially in the 6 months prior to admission. Both hospitalized and non-hospitalized youth had a higher average number of visits to office-based providers than their national counterparts. The study suggests that (1) greater awareness of morbidity and health care utilization patterns and risk behaviors may enhance prevention efforts; (2) use of instruments to capture more information on health habits and lifestyle may facilitate preventive interventions; (3) collaborations among pediatric primary care providers, the Information Services (IS) and Quality Management (QM) departments may facilitate this type of research in a managed care setting.