Implementation of electronic health record systems continues to grow. This study aimed to evaluate the impact of such a system on the use and quality of ambulatory care. Using two regions of Kaiser Permanente’s patient population, investigators collected data on utilization of office visits, lab, and radiology services, as well as quality measures from the Health Plan Employer Data and Information Set (HEDIS). Findings include a decrease in utilization of office visits, an increase in telephone contacts, and largely unaffected measures of quality. Authors conclude that introducing electronic health records may increase appropriate use of health care services and lead to noted changes in physician workflow.