Exit Rates of Accountable Care Organizations That Serve High Proportions of Beneficiaries of Racial and Ethnic Minority Groups

Importance The Medicare Shared Savings Program provides financial incentives for accountable care organizations (ACOs) to reduce costs of care. The structure of the shared savings program may not adequately adjust for challenges associated with caring for patients with high medical complexity and social needs, a population disproportionately made up of racial and ethnic minority groups. If so, ACOs serving racial and ethnic minority groups may be more likely to exit the program, raising concerns about the equitable distribution of potential benefits from health care delivery reform efforts. Objective To evaluate whether ACOs with a high proportion of beneficaries of racial and ethnic minority groups are more likely to exit the Medicare Shared Savings Program and identify characteristics associated with this disparity. Design, Setting, and Participants This retrospective observational cohort study used secondary data on Medicare Shared Savings Program ACOs from January 2012 through December 2018. Bivariate and multivariate cross-sectional regression analyses were used to understand whether ACO racial and ethnic composition was associated with program exit, and how ACOs with a high proportion of beneficaries of racial and ethnic minority groups differed in characteristics associated with program exit. Exposures Racial and ethnic composition of an ACO's beneficiaries. Main Outcomes and Measures Shared savings program exit before 2018. Results The study included 589 Medicare Shared Savings Program ACOs. The ACOs in the highest quartile of proportion of beneficaries of racial and ethnic minority groups were designated high-proportion ACOs (145 [25%]), and those in the lowest 3 quartiles were designated low-proportion ACOs (444 [75%]). In unadjusted analysis, a 10-percentage point increase in the proportion of beneficiaries of racial and ethnic minority groups was associated with a 1.12-fold increase in the odds of an ACO exit (95% CI, 1.00-1.25; P = .04). In adjusted analysis, there were significant associations among high-proportion ACOs between characteristics such as patient comorbidities, disability, and clinician composition and a higher likelihood of exit. Conclusions and Relevance The study results suggest that ACOs that served a higher proportion of beneficaries of racial and ethnic minority groups were more likely to exit the Medicare Shared Savings Program, partially because of serving patients with greater disease severity and complexity. These findings raise concerns about how current payment reform efforts may differentially affect racial and ethnic minority groups. This cohort study examines whether accountable care organizations with a high proportion of racial and ethnic minority groups are more likely to exit the Medicare Shared Savings Program. Question Are accountable care organizations (ACOs) that serve a high proportion of beneficaries of racial and ethnic minority groups more likely to exit the Medicare Shared Savings Program? Findings In this cohort study of 589 Medicare Shared Savings Program ACOs, from January 2012 to December 2018, ACOs with a higher proportion of patients of racial and ethnic minority groups were more likely to exit the Medicare Shared Savings Program. In multivariable analysis, the higher exit rate was associated with significant differences in beneficiary complexity and ACO structure. Meaning The study results suggest that ACOs that serve racial and ethnic minority groups are also more likely to serve beneficiaries with complex medical and social needs; recent changes in the payment structures of the Medicare Shared Savings Program may be associated with the exit of ACOs that serve these populations, which may be associated with racial and ethnic disparities in ACO access.