The Medicare Shared Savings Program (MSSP) was launched in 2012 to test the effectiveness of value-based care models in reducing costs and improving outcomes. Currently 561 Accountable Care Organizations (ACOs) participate in the program, covering more than 10.5 million beneficiaries. Combined, these ACOs are responsible for a net savings of $314 million between 2012 and 2017. The ACOs with the greatest savings and highest number of covered Medicare members in 2017 can be found in the following lists.

Most of the ACOs with the greatest earned savings spent well below their target benchmark. The median savings rate, or the percent difference between actual spending and an ACO’s assigned benchmark, was more than 11 percent for all ACOs that shared savings, which is higher than 8 of the top 10 ACOs that earned the greatest savings. Bigger ACOs, such as Advocate Physician Partners Accountable Care, didn’t have as much of a savings rate but made the list because of their large patient volume and associated reductions in spending.

However, having a larger beneficiary pool and presumably the existing infrastructure to manage significant numbers of patients, does not notably increase the likelihood of sharing in any savings. Though the minimum qualifying savings rate grows smaller for progressively larger organizations under CMS guidelines, only 3 of the top 10 largest ACOs by patient population had shared savings in 2017.

The following tables list the top-performing ACOs by shared savings earned, benchmark spending, and patient population served.