Medicaid expansions under the Affordable Care Act (ACA) dramatically increased access to insurance coverage. We examined whether the 2014 ACA Medicaid expansions also mitigated existing racial or ethnic disparities in preventable hospitalizations and emergency department (ED) visits. Using inpatient data from twenty-nine states and ED data from twenty-six states for the period 2011-18, we found that Medicaid expansions decreased disparities in preventable hospitalizations and ED visits between non-Hispanic Black and White nonelderly adults by 10 percent or more. There were no significant effects on disparities between Hispanic and non-Hispanic White nonelderly adults, possibly reflecting lower baseline differences and, separately, persisting coverage disparities. These findings highlight sustained improvements in community-level care for non-Hispanic Black populations, who historically lack access to care. Our findings also suggest access barriers experienced by Hispanic adults that need to be addressed beyond Medicaid eligibility expansion.