Physical activity can reduce the risk of at least 20 chronic diseases and conditions and provide effective treatment for many of these conditions. Yet, physical activity levels of Americans remain low, with only small improvements over 20 years. The Centers for Disease Control and Prevention (CDC) considered what would accelerate progress and, as a result, developed Active People, Healthy NationSM, an aspirational initiative to improve physical activity in 2.5 million high school youth and 25 million adults, doubling the 10-year improvement targets of Healthy People 2020. Active People, Healthy NationSM will implement evidence-based guidance to improve physical activity through 5 action steps centered on core public health functions: (1) program delivery, (2) partnership mobilization, (3) effective communication, (4) cross-sectoral training, and (5) continuous monitoring and evaluation. To achieve wide-scale impact, Active People, Healthy NationSM will need broad engagement from a variety of sectors working together to coordinate activities and initiatives.