Heterogeneous Effects of Affordable Care Act Medicaid Expansions Among Women with Dependent Children by State-Level Pre-Expansion Eligibility.

This study explores the heterogeneity in effects of the 2014 Affordable Care Act (ACA) Medicaid expansions on insurance coverage, health care access, and health status of low-income women with dependent children by pre-expansion state-level income eligibility. We employ a quasiexperimental difference-in-differences design comparing outcome changes in Medicaid expansion states to nonexpansion states. We estimate effects separately for three groups of expansion states based on pre-expansion (2013) parent income eligibility: low pre-expansion eligibility (<90% of federal poverty level [FPL]), high eligibility (90% to <138% FPL), and full eligibility (≥138% FPL). Study samples include women with dependent children below 138% FPL from the 2011 to 2018 American Community Survey for the insurance outcomes, and from the 2011 to 2018 Behavioral Risk Surveillance System for the access and health outcomes. There is stark heterogeneity in changes of health insurance and health care access by pre-expansion income eligibility levels. In comparison to Medicaid non-expansion states, there are large increases in insured rate (9 percentage-points) and Medicaid coverage (16 percentage-points) in expansion states with low pre-expansion eligibility. Insurance changes are much smaller in states with high or full pre-expansion eligibility. Changes in access largely mirror those in coverage. There are no significant changes in health status regardless of pre-expansion eligibility. The ACA Medicaid expansions increased coverage and access for low-income women with dependent children primarily in states with low pre-expansion parent eligibility, and therefore, reduced differences in these outcomes between expansion states.