Reviving the promise of primary care: redesigning service delivery to promote core functions

<h2>Summary</h2> Although primary care can reduce morbidity, increase lifespans, and improve health equity, it is underperforming globally. As health systems adapt with evolving funding, technology, and demographic conditions, the role of primary care in achieving health for all needs to be clearly explained. Redesigning primary care around four main functions (ie, being the first choice for most health needs; detecting illnesses and risks; providing high-quality care across the life course; and linking to advanced care and social systems) can optimise its benefits within broader systems. In this Viewpoint, we reassert the core functions of primary care, describe design features that promote the core functions, and introduce models that effectively leverage these functions to address emerging health-system challenges.