Medicare accountable care organization characteristics associated with participation in 2-sided risk.

Purpose: To examine the associations of accountable care organization (ACO) characteristics with the likelihood of participation in 2-sided risk tracks in the Medicare Shared Savings Program (SSP).
Methods: CMS ACO Public Use Files and Provider-Level Research Identifiable Files were used to trace Medicare ACOs' participation in the SSP between 2012 and 2020 and measure ACO characteristics, including size, rurality of the service area, affiliation with supporting organizations, program experience, and performance. Logistic regression and survival analysis were used to test the associations between ACO characteristics and the probability of ACOs initially participating in or subsequently switching to 2-sided risk tracks.
Findings: Among the 624 Medicare SSP ACOs that started between 2012 and 2017, 26 participated in 2-sided risk tracks in their initial contracts and 95 switched to 2-sided risk tracks subsequently. ACO characteristics were not significantly associated with the probability of participating in 2-sided risk tracks in initial contracts. ACO size, affiliation with supporting organizations, and performance were positively associated with the likelihood of switching to 2-sided risk. Rural ACOs were less likely to switch to 2-sided risk than their urban counterparts.
Conclusions: Small and rural ACOs are less prepared to transition into 2-sided risk swiftly.
(© 2022 National Rural Health Association.)