Pioneer ACO Model

The Pioneer Accountable Care Organization (ACO) Model was designed for health care organizations and providers that were already experienced in coordinating care for patients across care settings. It allowed these provider groups to move more rapidly from a shared savings payment model to a population-based payment model on a track consistent with, but separate from, the Medicare Shared Savings Program. And it was designed to work in coordination with private payers by aligning provider incentives, which improved quality and health outcomes for patients across the ACO, and achieved cost savings for Medicare, employers and patients.


Pioneer ACOs mapped.

The Pioneer ACO Model began with 32 ACOs in 2012 and concluded December 31, 2016 with 9 ACOs participating. (List)

  • Alina Health (Minnesota and Western Wisconsin)
  • Atrius Health (Eastern and Central Massachusetts)
  • Banner Health Network (Phoenix, Arizona Metropolitan Area Maricopa and Pinal Counties)
  • Beth Israel Deaconess Physician Organization (Eastern Massachusetts)
  • Fairview Health Systems (Minneapolis, Minnesota Metropolitan Area)
  • Michigan Pioneer ACO (Southeastern Michigan)
  • Monarch Healthcare (Orange County, California)
  • Montefiore ACO (New York City (the Bronx) and lower Westchester County, New York)
  • Partners Healthcare (Eastern Massachusetts)

Model Details

The payment models that were tested in the first two years of the Pioneer ACO Model were a shared savings payment policy which had generally higher levels of shared savings and risk for Pioneer ACOs than levels proposed in the Medicare Shared Savings Program. In the third year of the program, participating ACOs that showed a specified level of savings over the first two years were eligible to move a substantial portion of their payments to a population-based model. These models of payments were also flexible to accommodate the specific organizational and market conditions in which Pioneer ACOs worked.

Quality and financial results are provided for Performance Year 1 (2012), Performance Year 2 (2013), Performance Year 3 (2014), Performance Year 4 (2015) and Performance Year 5 (2016):

The results provide the total number of beneficiaries aligned to a given Pioneer ACO, benchmark expenditures to which ACO expenditures are compared, actual ACO expenditures and payment from CMS to the ACO as shared savings or paid from the ACO to CMS as shared losses. In order to receive savings or owe losses in a given year, ACO expenditures must be outside a minimum corridor set by the ACO's minimum savings rate (MSR) and minimum loss rate (MLR). If savings/loss is within this corridor, no payment is made to the ACO or owed to CMS. If the Gross Savings/Losses percentage is outside this corridor, then the ACO splits the overall savings/loss with CMS.

Additional Information

General Information

Performance Results

Press Releases

Case Studies


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