Since the passage of the Affordable Care Act, the field of population health has evolved and matured considerably. Improving quality and health outcomes along with lowering costs has become an ongoing focus in delivery of health care. The new Third Edition of Population Health reflects this focus and evolution in today's dynamic healthcare landscape by conveying the key concepts of population health management and examining strategies for creating a culture of health and wellness in the context of health care reform. Offering a comprehensive, forward-looking approach to population health, the Third Edition's streamlined organization features 14 chapters divided among 3 major sections: Part I – Population Health in the US discusses health and wellness vs. healthcare delivery; epidemiology and the impact of social determinants. Part 2 –The Population Health Ecosystem looks at structures and systems; value-based payment models, population health informatics /analytics; and developing the population health workforce; Part 3 – Creating Culture Change explores health promotion and consumer engagement; implementing organizational culture change; care coordination; accountability for outcomes; and policy and advocacy.