Accountable Care Organizations and Population Health Organizations.

Accountable care organizations (ACOs) and hospitals are investing in improving "population health," by which they nearly always mean the health of the "population" of patients "attributed" by Medicare, Medicaid, or private health insurers to their organizations. But population health can and should also mean "the health of the entire population in a geographic area." We present arguments for and against ACOs and hospitals investing in affecting the socioeconomic determinants of health to improve the health of the population in their geographic area, and we provide examples of ACOs and hospitals that are doing so in a limited way. These examples suggest that ACOs and hospitals can work with other organizations in their community to improve population health. We briefly present recent proposals for such coalitions and for how they could be financed to be sustainable.