Background: Early onset colorectal cancer (EO-CRC, age < 50 years) is an emerging public health crisis, especially in minorities. We evaluated and compared the effects of Medicaid expansion on the incidence of EO-CRC among Hispanics, Blacks, and Whites across the United States. Methods: The National Cancer Data Base was used to collect data on newly diagnosed cases of EO-CRC (40-49 years) among the three races, across all stages, from 2010-2017. Data for 21 expansion states (ES) that expanded Medicaid in 2014, and 16 non-expansion (NES) states was analyzed, excluding the states which expanded after 2014.The yearly state-wise population of all three races was collected from the U.S Census Bureau for 2010-17. A segmented Poisson regression model with generalized estimating equations was used for statistical analysis. Results: Annual incidence (AI) of EO-CRC pre and post expansion, in ES was 6/100,000 and 9/100,000 in Hispanics; 17/100,000 and 21/100,000 in Blacks and 14/100,000 and 18/100,000 for Whites. In NES the AI, pre and post 2014 was 8/100,000 and 10/100,000 among Hispanics, 19/100,00 and 24/100,000 among Blacks and 16/100,000 and 20/100,000 among Whites. Rate of change in AI of EO-CRC among Hispanics was 4.3% per year (2010-14), and 9.8% (2014-17) for ES states; and 6.4% (2010-14), and 1% (2014-17) in NES; among blacks was 3.8 % per year (2010-14), and 1.3% (2014-17) for ES states; and 1.6% (2010-14), and 3.2% (2014-17) in NES. Among Whites, increase in AI was 4.3% per year (2010-14), and 6.3% (2014-17) for ES states; and 4.0% (2010-14), and 5.7% (2014-17) in NES. ES showed greater change in incidence after expansion compared to pre-expansion in the incidence of EO-CRC as compared to NES (p=0.03) in Hispanics, however no significant difference was noted among Blacks (p=0.33) and Whites(p=0.94). Racial groups did significantly differ with respect to the degree of change in pre and post expansion (2014) rates of incidence of EO- CRC in the ES, however, in the NES, there were significant difference between the Hispanics and Whites (p=0.01), but not between Blacks versus Whites. Conclusions: Medicaid expansion reduces racial disparities in detection of EOCRC.