As in previous years, MSSP ACOs showed strong performance on quality of care measures. But many of the proposed reforms in the program center on whether a redesign could increase the modest savings that have been estimated by the Medicare actuaries and other researchers in the program to date. In this, the first post of a two-part discussion, we provide a summary and perspective on the MSSP results. In part II to be published tomorrow, we describe some potential implications for further reforms in the program, based on the factors associated with stronger performance, and the substantial variation in performance across individual ACOs.
Our analysis reflects ACO performance relative to their own spending benchmarks, set according to a regulatory formula that CMS is proposing to modify. Such a benchmark is not necessarily a measure of the savings that health care organizations would have achieved in the absence of the ACO program; there are many reasons why a benchmark may differ. Analyses that have sought to assess the counterfactual – what would Medicare spending have been in the absence of the MSSP program – have shown larger MSSP program savings that increase over time. Notable research has been published here and here and summarized here, here and here – increasing to up to 2% of program costs by a few years after implementation. Most recently, a study published on September 5, 2018, analyzed the first three years of the MSSP program, finding that MSSP benchmarks underestimated spending reduction by 39%, and underestimated net savings to Medicare by a factor of 2.8. However, analyses based on benchmark comparisons can provide insights about ACO performance relevant to program design, and benchmarks are also a standard against which the program is judged.