Medicare Advantage versus Traditional Medicare for Dual Eligible Beneficiaries

Project Summary/Abstract Dual-eligible Medicare and Medicaid beneficiaries (“duals”) frequently have complex clinical and social needs. Compared with non-duals, dual beneficiaries are poorer, more likely to qualify for Medicare due to disability, and be racial and ethnic minorities. Structuring health benefits to meet the needs of duals is challenging due to

fragmented financing and poor coordination between the two programs. Private Medicare Advantage plans could be a potentially promising vehicle for better integrating Medicare and Medicaid benefits. Duals are increasingly enrolling in MA plans with over half (56%) of 12 million duals enrolled in MA in 2022. The relative

value of MA vs. Traditional Medicare (TM) remains uncertain, however, and evidence on differences in care patterns and outcomes for duals in MA vs. TM is extremely limited. Moreover, because of potential differential selection into MA, estimating causal effects of MA vs. TM on outcomes is challenging. This study will examine

longitudinal enrollment patterns among Medicaid beneficiaries as they qualify for Medicare, and assess beneficiary-, county-, and state-level predictors of enrollment in MA vs. TM and enrollment continuity (Aim 1). To assess the effects of MA vs. TM on utilization and outcomes, we will compare Medicaid utilization and

spending for duals in MA vs. TM, including long-term services and supports (LTSS) and Medicaid-covered behavioral health services (Aim 2), and Medicare utilization and spending (e.g., prescription drug adherence, hospitalizations, post-acute care, and mortality, Aim 3). We will use individual-level Medicaid and Medicare

enrollment, claims, and managed care encounter data, 2019-2026, linked with detailed information on county- level MA plan offerings and state-level policies to accomplish these aims. To estimate the effects of MA enrollment and address potential selection bias in Aims 2 and 3, we will leverage a natural experiment created

by recent policies that permit automatic enrollment of Medicaid managed care enrollees in MA plans when they qualify for Medicare. Across all aims, we will assess variation in MA effects for dual beneficiaries who qualify for Medicare due to disability (