Trends in Medicaid Take-Up Among Eligible Adults After the Affordable Care Act Medicaid Expansions: 2014-2019.

Little is known about how take-up of Medicaid among eligible adults has changed since 2014. This study used data from the Medical Expenditure Panel Survey to examine changes in Medicaid enrollment among Medicaid-eligible adults between 2014 and 2019. Eligibility for Medicaid was simulated using state- and year-specific eligibility rules. Among all Medicaid-eligible citizen adults aged 19-64 years, the proportion enrolled in Medicaid increased from 55.5% in 2014-2015 to 61.9% in 2016-2017, and then remained approximately at the same level in 2018-2019 (61.5%). Among adults who became eligible because of the Medicaid expansions, the proportion enrolled in Medicaid increased from 44.1% in 2014-2015 to 53.8% in 2016-2017. Among pre-Affordable Care Act (ACA)-eligible adults, there was no statistically significant change in the proportion enrolled in Medicaid between 2014-2015 and 2016-2017 (66.8% and 69.7%, respectively). There were significant differences in changes in take-up rates across population subgroups.