ABSTRACT: Importance:Millions of Americans gained insurance through the state expansion of Medicaid, but several states with large populations of racial/ethnic minorities did not expand their programs. Objective:To investigate the implications of Medicaid expansion for liver transplant (LT) wait-listing trends for racial/ethnic minorities. Design, Setting, and Participants:A cohort study was performed of adults wait-listed for LT using the United Network of Organ Sharing database between January 1, 2010, and December 31, 2017. Poisson regression and a controlled, interrupted time series analysis were used to model trends in wait-listing rates by race/ethnicity. The setting was LT centers in the United States. Main Outcomes and Measures:(1) Wait-listing rates by race/ethnicity in states that expanded Medicaid (expansion states) compared with those that did not (nonexpansion states) and (2) actual vs predicted rates of LT wait-listing by race/ethnicity after Medicaid expansion. Results:There were 75?748 patients (median age, 57.0 [interquartile range, 50.0-62.0] years; 48?566 [64.1%] male) wait-listed for LT during the study period. The cohort was 8.9% Black and 16.4% Hispanic. Black patients and Hispanic patients were statistically significantly more likely to be wait-listed in expansion states than in nonexpansion states (incidence rate ratio [IRR], 1.54 [95% CI, 1.44-1.64] for Black patients and 1.21 [95% CI, 1.15-1.28] for Hispanic patients). After Medicaid expansion, there was a decrease in the wait-listing rate of Black patients in expansion states (annual percentage change [APC], -4.4%; 95% CI, -8.2% to -0.6%) but not in nonexpansion states (APC, 0.5%; 95% CI, -4.0% to 5.2%). This decrease was not seen when Black patients with hepatitis C virus (HCV) were excluded from the analysis (APC, 3.1%; 95% CI, -2.4% to 8.9%), suggesting that they may be responsible for this expansion state trend. Hispanic Medicaid patients without HCV were statistically significantly more likely to be wait-listed in the post-Medicaid expansion era than would have been predicted without Medicaid expansion (APC, 13.2%; 95% CI, 4.0%-23.2%). Conclusions and Relevance:This cohort study found that LT wait-listing rates have decreased for Black patients with HCV in states that expanded Medicaid. Conversely, wait-listing rates have increased for Hispanic patients without HCV. Black patients and Hispanic patients may have benefited differently from Medicaid expansion.