For the past three decades, the "Healthy People" initiative has represented an ambitious yet achievable health promotion and disease prevention agenda for the nation. The recently released fourth version--"Healthy People 2020"--builds on the foundations of prior iterations while newly embracing and elevating a comprehensive "social determinants" perspective. By clearly articulating a new overarching goal to "create social and physical environments that promote good health for all" and a new topic area dedicated to defining the social determinants of health approach, it breaks new ground. Specifically, the 2020 plan emphasizes the need to consider factors such as poverty, education, and numerous aspects of the social structure that not only influence the health of populations but also limit the ability of many to achieve health equity. Improving health is too multifaceted to be left to those working in the health sector alone. Using a social determinants approach can reframe the way the public, policy makers, and the private sector think about achieving and sustaining health. This article describes why such a social determinants approach can enhance our collective efforts to improve population health. This is achieved by defining the context for this new perspective, the process by which the "Healthy People 2020" goals and objectives were developed, and the challenges and opportunities ahead. Adding this broad, social determinants perspective and vision for shared societal responsibility for change leaves "Healthy People 2020" poised to promote a stronger legacy for a healthier nation and reaffirm a unity of purpose for the future. (Contains 1 table.)