The opportunities and challenges of the MSSP ACO program: a report from the field.

In this article, we seek to provide the first detailed description of a Medicare Shared Savings Program (MSSP) accountable care organization (ACO)'s actions and results to help increase understanding of the challenges and opportunities facing ACOs, and in particular, those comprised of a network of independent practices. Whether ACOs have been successful in delivering value has been the subject of much debate and speculation. What has been missing from this discussion is a look at the program from the frontlines and those who are launching and running MSSP ACOs.