The fundamental goal of health care is to improve the health of the public. Abundant evidence indicates that health care systems built on a solid foundation of primary care deliver more effective, efficient, and equitable care than systems that fail to invest adequately in primary care. Primary care is endangered in the United States, and confronts major challenges worldwide. The chief external threats consist of the failure to invest an adequate share of the nation’s health care resources in primary care and to assure all people access to affordable and high quality primary care. The principal internal threats consist of changing population health needs and the growing clinical demands of primary care practice, which create barriers for clinicians and organizations in innovating and implementing new practice models. The Center for Excellence in Primary Care (CEPC) was created in 2005 to respond to these challenges. CEPC identifies, develops, tests, and disseminates promising innovations in primary care to improve the patient experience, enhance population health and health equity, reduce the cost of care, and restore joy and satisfaction in the practice of primary care. CEPC provides training in team-based care, offers practice facilitation to spur and support transformation, broadens the evidence base through research and evaluation, and advocates for policy that promotes high performing primary care.