BackgroundThe effect of years of education on the maintenance of healthy cognitive functioning may differ by race and ethnicity given historical and ongoing inequities in educational quality.MethodsWe examined 20,311 Black, Latinx, and White adults aged 51–100 from the Health and Retirement Study (2008–2016). Telephone Interview for Cognitive Status‐27 data was used to measure cognitive functioning. Generalized additive mixed models were stratified by race and ethnicity and educational attainment (≥12 vs. <12 years). Selected social determinants of health, all‐cause mortality, time‐varying health and healthcare utilization characteristics, and study wave were included as covariates.ResultsOn average, Black and Latinx adults scored lower at baseline compared to White adults regardless of educational attainment (p < 0.001), with a significant overlap in the distributions of scores. The rate of cognitive decline was non‐linear for Black, Latinx, and White adults (p < 0.001), and a period of stability was witnessed for those with higher educational attainment irrespective of race and ethnicity. Compared to Black, Latinx, and White adults with lower educational attainment, higher‐educated White adults received the greatest protection from cognitive decline (13 years; 64 vs. 51), followed by Latinx (12 years; 67 vs. 55), and Black adults (10 years; 61 vs. 51). Latinx adults experienced cognitive decline beginning at a later age.ConclusionsThe extent to which higher educational attainment protects adults from cognitive decline differs by race and ethnicity, such that higher‐educated White adults received a greater benefit than higher‐educated Black or Latinx adults.