In this discussion paper, Glen Mays describes recent experimentation with population health strategies that has been spurred by the ACA and by state health reform. Population health strategies involve varied stakeholders in the public and private sectors. The evolution in the landscape of actors, along with ACA implementation and factors including economic challenges, are leading to a reexamination of how governmental public health agencies are organized, and of their activities and financing. An IOM report and other sources have described the heterogeneity of public health agencies and their activities, which in some cases include the provision of clinical health care services, and similar heterogeneity in how those activities are financed. Aside from inefficiencies, heterogeneity is problematic because it creates deep disparities in the level of health protection received by communities.