Amid the global pandemic, it becomes more apparent that diabetes is a pressing health concern because racial/ethnic minorities with underlying diabetes conditions have been disproportionately affected. The study proposes a multiyear examination to document the role of the Affordable Care Act (ACA) in racial/ethnic disparities in diabetes health. Using the Behavioral Risk Factor Surveillance System from 2011 to 2019, the study with a pre-post design investigated changes in access to care and diabetes health among non-White minorities compared with Whites before and after the ACA by conducting multivariable linear regression, with state-fixed effects and robust standard errors. Compared with Whites, racial/ethnic minorities showed significant improvements in health insurance coverage, having a personal doctor, and not seeing a doctor because of cost. Blacks (3.2% points, P ≤ 0.000), Hispanics (1.6% points, P = 0.001), and “other” racial/ethnic group (1.5% points, P = 0.003) experienced a greater increase in diagnosed prediabetes than Whites, whereas no and small differences were found in diagnosed diabetes and obesity, respectively. The yearly comparisons of changes in diagnosed prediabetes showed that Blacks compared with Whites had a growing increase from 1.2% points (P = 0.001) in 2014 to 3.3% points (P = 0.001) in 2019. Insurance coverage has declined after 2016, and obesity had an increasing trend across race/ethnicity. The ACA had a positive role in improving access to care and identifying those at risk for diabetes to a larger extent among racial/ethnic minorities. However, the policy impacts have been diminishing in recent years. Continued efforts are needed for sustained policy effects.