Medicaid Expansion, Managed Care Plan Composition, and Enrollee Experience

OBJECTIVES: To examine changes in plan composition and enrollee experience associated with Medicaid expansion among Medicaid managed care organization (MCO) enrollees. STUDY DESIGN: Using 2012-2018 Adult Medicaid Consumer Assessment of Healthcare Providers and Systems surveys, we estimated changes in MCO enrollee characteristics and 4 outcomes: having access to needed care, having a personal doctor, having timely access to a checkup, and having timely access to specialty care. METHODS: We estimated multivariable linear probability models comparing pre-vs postexpansion changes in expansion vs nonexpansion states. The postexpansion period was modeled as an event-study regression to account for changes over time. The coefficient of interest was a Medicaid expansion-by-year term. RESULTS: Medicaid expansion was associated with statistically significant decreases in the proportion of female enrollees (-8.4 percentage points [PP]; P < .01) and increases in the proportion of enrollees who were aged 55 to 64 years (6.8 PP; P < .01) and were non-Hispanic White (4.4 PP; P < .01). Relative to enrollees in nonexpansion states, MCO enrollees in expansion states were significantly less likely to report access to a personal doctor (-1.6 PP; 95% CI, -3.0 to -0.1 PP) and less likely to report timely access to specialty care (-2.1 PP; 95% CI, -3.4 to -0.8 PP; P < .01) in the first year after expansion. Differences were not statistically significant by the second year post expansion. There were not significant changes in the other 2 outcomes. CONCLUSIONS: State policy makers may need to account for the role that Medicaid expansion may have in changing Medicaid MCO enrollee composition to prevent unfair penalization on performance metrics.

Automated summary

This study examines the impact of Medicaid expansion on plan composition and enrollee experience among Medicaid managed care organization (MCO) enrollees. The results show that Medicaid expansion is associated with a decrease in the proportion of female enrollees and an increase in the proportion of enrollees aged 55 to 64 years and non-Hispanic White enrollees. MCO enrollees in expansion states are less likely to report having a personal doctor and timely access to specialty care in the first year after expansion, but these differences are not statistically significant in the second year.