This study compares access to primary care, utilization, and costs among enrollees in four forms of managed care and an indemnity plan. We use 1996 data from a commercial insurer. Most managed care enrollees had better access to primary care services than indemnity enrollees. This access was associated with a generally lower rate of preventable hospitalization. Per capita inpatient costs were notably lower in managed care plans than in the indemnity plan. We describe how health care managers can use readily available administrative data and straightforward statistical techniques to enhance routine monitoring for quality and costs. Policy makers can use this approach to identify health services trends, and to evaluate access to health services for individuals enrolled in various benefit plan types.