With accountable care organizations (ACOs) soon to serve more than a million Medicare patients, it is clear that this model of care delivery is receiving an unprecedented test of its viability, and, if it works as intended, may reshape how healthcare is paid for on a larger scale. Cigna alone plans to have more than a million people enrolled in ACOs by 2014, and says it believes that ACOs are going to be important regardless of the Supreme Court’s ruling on the Patient Protection and Affordable Care Act (PPACA).

With so much focus on the topic, it’s worth taking a look back at some of the research and analysis on ACOs published by Milliman on the topic over the past couple of years.

First, for a good summary of ACOs—what they are and how they work—start with this overview video featuring a number of Milliman experts.

For many observers, the key question about ACOs is whether they represent a financially viable model compared to fee-for-service. Effective financial management will be key to success. Milliman has produced a number of relevant papers:

• “Nuts and Bolts of ACO Financial and Operational Success: Calculating and Managing to Actuarial Utilization Targets” provides significant operational detail on dealing with utilization in an ACO context.
• “ACO Gain/Loss Sharing” proposes a framework for allocating savings within an ACO that emphasizes rewards for an ACO’s component entities based on their relative contributions to the organization’s total shared savings and quality performance. Such a framework is required when applying as a Medicare ACO, but the Centers for Medicare and Medicaid Services (CMS) has not provided a detailed procedure for creating one. This paper tries to help fill that gap.
• “A First Look at ACO’s Risky Business: Quality Is Not Enough” discusses downside risk faced by Medicare ACOs; while somewhat dated at this point it still contains some useful concepts.
• “Pioneer ACOs: Quantifying Risks and Identifying Opportunities” focuses on how Pioneer ACOs can control costs and identify savings opportunities given the additional risks they face.

 
With all the attention on Medicare ACOs, it’s easy to forget that they exist in the private market, as well. For more on such entities, look at “ACOs Beyond Medicare,” which describes the potential advantages for providers who partner with a private insurer rather than with CMS. A 2011 Managed Healthcare Executive roundtable featuring Milliman consultant Rob Parke also discussed ACOs in the private market.

A number of other papers have also been published discussing various aspects of ACOs such as:

• The use of care management guidelines in managing ACOs
• Patient attribution
• The role of nurses in accountable care