This article--the first in a series on primary care--outlines the daunting challenges facing primary care today. Most people in the United States desire a primary care "home" to provide for and coordinate their health care needs. Yet primary care is endangered by physician stress, inadequate performance in managing chronic illness, and inability to provide prompt access and reliable continuity of care. Fundamental redesign is needed to improve access to and quality of care while easing physicians' workload without causing major increases in health care costs.