Accountable Care Organization (ACO) Market Penetration in Rural Counties

The RUPRI Center has been researching the growth of Accountable Care Organizations (ACOs) and their spread into rural areas since the onset of the Medicare Shared Savings Program (SSP). RUPRI Center publications have found (similar to Centers for Medicare & Medicaid Services publications) that beneficiary assignment to ACOs grew dramatically between 2013 and 2018 but has remained relatively stable since then [RUPRI brief 2026-9]. That same work showed that 16.9 percent of beneficiaries enrolled in both Medicare Part A and Part B were assigned to an ACO, with assignment of beneficiaries in micropolitan and noncore counties occurring at a slightly higher rate than those in metropolitan counties. Earlier Center work showed that new SSP ACOs with a significant rural presence were relatively uncommon in the early years of the program. But in 2022, such ACOs comprised more than one-third (34.8 percent) of new SSP ACOs [RUPRI brief 2026-2].

This project will update all of these findings and produce a broad snapshot of the rural ACO landscape. It will tell the story of the evolution of the SSP, empirically with trends in number of beneficiaries, providers (by type – Rural Health Clinics, Federally Qualified Health Centers, Critical Access Hospitals, Private Clinics, PPS Hospitals), and governance (hospital-led, physician-led, hybrid). Defining rural ACOs using a previously produced methodology [RUPRI, 2/2026], the project will explore reasons for new rural ACOs, rural ACOs that continue after their initial agreement, and formation of new rural ACOs.