Performance in the Medicare Shared Savings Program by Accountable Care Organizations Disproportionately Serving Dual...

The growth of accountable care organizations (ACOs) and other alternative payment models has prompted concern about whether these models will disadvantage providers who serve vulnerable populations, particularly those living in poverty or with a disability.

To examine performance by ACOs in the top quintile of their proportion of beneficiaries dually enrolled in Medicare and Medicaid (high-dual) and the top quintile of disabled beneficiaries (high-disabled).

This is a retrospective cohort study.

The 333 ACOs in the Medicare Shared Savings Program in 2014, followed through 2016.

Quality scores, savings per beneficiary, whether or not the ACO shared savings, and amount of shared savings.

High-dual and high-disabled ACOs had slightly lower quality and similar or higher baseline spending than other ACOs, but achieved greater savings per beneficiary than other ACOs ($212 vs. $51 for high-dual ACOs, P=0.04; $241 vs. $44 for high-disabled ACOs, P=0.012). Further, these ACOs were equally or more likely to earn shared savings; just over 30% of high-dual ACOs earned shared savings compared with 25% of non-high-dual ACOs (P=0.35) and 38% of high-disabled ACOs earned shared savings compared with 23% of non-high-disabled ACOs (P=0.013). In longitudinal analyses, we found a decrease in the differences in quality between high-social risk and other ACOs over time. Savings remained higher for high-dual and high-disabled ACOs relative to other ACOs over 2014-2016 though the gap narrowed over time.

High-dual and high-disabled ACOs had similar or higher spending than other ACOs at baseline, but achieved greater savings and were equally or more likely to earn shared savings, suggesting that alternative payment models can have positive financial outcomes for providers who serve vulnerable populations.