Patient-centered care has recently been elevated as a health care priority, and patient surveys play a central role. The Massachusetts Ambulatory Care Experiences Survey Project tested the feasibility of measuring patients' experiences with individual physicians. Patients of 215 primary care physicians statewide completed the survey. Ambulatory Care Experiences Survey produces 11 summary measures in two broad areas: physician-patient interactions and organizational processes. Substantial variability in physician performance was observed; while minimal variance was associated with health plans or physician networks. With 40 completed surveys per physician, nine measures exceeded accepted thresholds for reliable physician-level measurement. Performance reporting frameworks assured misclassification risk ≤2.5%. The project demonstrates the feasibility and value of obtaining high quality information about patients' experiences with individual physicians.