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.