A major contributor to shortfalls in delivery of recommended health care services is lack of physician time. On the basis of recommendations from national clinical care guidelines for preventive services and chronic disease management, and including the time needed for acute concerns, sufficiently addressing the needs of a standard patient panel of 2,500 would require 21.7 hours per day. The problem of insufficient time indicates that primary care requires broad, fundamental changes. The creation of primary care teams that include members such as physician assistants, nurse practitioners, dietitians, health educators, and lay coaches is important to meeting patients' primary care needs.