Evaluation of CMMI Accountable Care Organization Initiatives: Pioneer ACO Evaluation Findings from Performance Years One and Two

This report presents emerging findings from an ongoing evaluation of the effects of the Pioneer Accountable Care Organization (ACO) model on Medicare spending, utilization, and quality in their first two performance years, calendar years 2012 (PY1) and 2013 (PY2).

We estimate that the 32 Pioneer ACOs significantly reduced Medicare expenditures during the first two performance years compared to their near markets’ underlying trends, which reflect how expenditures would have changed in absence of the Pioneer ACO model. These relative reductions translate into a total savings of approximately $384 million in the first two years of the Pioneer model, with the majority of these savings occurring in the first performance year ($279.7 million in PY1; $104.5 million in PY2). The savings translate into $35.62 per-beneficiary-per-month (PBPM) in 2012 and $11.18 PBPM in 2013. These pooled spending and utilization measures in Table 1 aggregate the point estimates for all Pioneer ACOs, and, therefore, the estimated impact of the entire Pioneer model.