Objective: This study seeks to refine the analysis of the effects of alcoholism treatment on subsequent use of medical care by examining components of the latter. Method: Claims and encounter data of 29,122 adults (mean age 40, 35% female) receiving benefits from both a mental health managed care program and its parent medical care insurance company who had a diagnosis of alcoholism were analyzed using a longitudinal Poisson regression model fit by the generalized estimating equation method to compare differences between the groups in medical utilization before and after alcoholism treatment. The diagnoses associated with medical care were assigned to one of four groups: alcohol specific, alcohol acute, alcohol chronic and nonalcohol related. All persons applying for alcoholism treatment benefits were included; those who had fewer than four visits for alcoholism treatment served as controls. Results: The largest effect of alcoholism treatment is seen for medical encounters associated with diagnoses that reflect the acute effects of intoxication. The frequency of encounters related to conditions associated with chronic alcohol misuse were the only type that did not significantly decline 1 year past treatment in the outpatient treatment group. Conclusions: This study provides support for the belief that treatment for alcoholism is directly associated with a change in medical care use. However, the findings suggest that the impact on utilization varies with the type of medical care. The most pronounced effects appear to be for acute problems that may be most directly attributed to the effects of active drinking. Changes in medical utilization in this area, therefore, may be responsible for the cost-offset of alcoholism treatment that has been observed in prior research.