Population health, public health, and accountable care: emerging roles and relationships.

To identify roles for public health agencies (PHAs) in accountable care organizations (ACOs), along with their obstacles and facilitators, we interviewed individuals from 9 ACOs, including Medicare, Medicaid, and commercial payers. We learned that PHAs participate in ACO-like partnerships with state Medicaid agencies, but interviewees identified barriers to collaboration with Medicare and commercial ACOs, including Medicare participation requirements, membership cost, risk-bearing restrictions, data-sharing constraints, differences between medicine and public health, and ACOs' investment yield needs. Collaboration was more likely when organizations had common objectives, ACO sponsors had substantial market share, PHA representatives served on ACO advisory boards, and there were preexisting contractual relationships. ACO-PHA relationships are not as straightforward as their shared use of the term "population health" would suggest, but some ACO partnerships could give PHAs access to new revenue streams.