Interest in Accountable Care Organizations (ACOs) accelerated with the passage of the Affordable Care Act, which established ACOs as a new payment model under Medicare and provided authorization and funding for the Center for Medicare and Medicaid Innovation (CMMI) to establish pilot programs to accelerate testing and implementation. Recognizing that new payment models are inevitable and faced with uncertainty about the relative benefits and risks of participation in federal programs, providers have begun to form organizations with the potential to become ACOs and are exploring (or have established) ACO contracts with private payers.

Whether ACOs will achieve their promise remains far from certain. Three challenges seem particularly important. First, given the scope of public and private activity already underway, there is a relatively narrow window of opportunity to put in place an evaluation framework that supports rapid learning, timely correction of policy and organizational missteps, and broad dissemination of successful organizational and policy approaches to ACO implementation (Fisher, Shortell JAMA 2010). Second, because CMMI will focus its evaluation efforts on public initiatives, it will be critical to establish some level of evaluation of private initiatives and to align, if possible, public and private evaluation initiatives. Some evaluation initiatives are already underway in the private sector, and although a small working group has been established to share information about these private sector efforts, there is as yet no well-defined path to coordinating public and private evaluation programs. Third, the key unintended consequences of ACO implementation lie at the intersection of public and private interests: savings in one segment of the population could occur at the expense of increased costs for the other; and whether ACO implementation will lead to a slowing of the local medical arms races already underway is unknown.

This project intends to address several of these barriers. The specific aims of this project are:

1. To continue to convene the ACO evaluation workgroup in order to monitor the progression of evaluation initiatives across private- and public-funded ACOs and help to facilitate the development of an aligned evaluation agenda.
2. To advance our understanding of factors that influence the formation, structure, contract, and capabilities of ACOs, by developing, pilot testing and implementing an annual survey of ACOs and ACO-like organizations.
3. To advance our understanding of factors that contribute to successful ACO formation by conducting a series of in-depth qualitative interviews and a small subset of confirmatory site visits to ACOs, with a particular focus on the formation of multi-payer ACOs.

We expect the project to contribute significantly to the understanding of how ACO formation is progressing nationally.