Background. Socioeconomic status (SES) indicators such as education and income influence population health including but not limited to self-rated health (SRH). Based on Minorities' Diminished Returns (MDRs), however, we observe weaker health effects SES indicators for non-Hispanic Blacks compared to non-Hispanic Whites. While such diminished returns of SES resources are shown in nationally representative data and Michigan data, there is still a need to replicate these findings in other settings. This is particularly relevant because the effects of social SES indicators are not universal but vary across geographic locations. This cross-sectional study tested racial differences in the effects of high educational attainment and income on SRH among Californian adults. Methods. Survey of California Adults on Serious Illness and End-of-Life is a representative survey of Californian adults conducted for the California Health Care Foundation. The independent variables were educational attainment and income. The main outcome was poor/fair SRH. Age, gender, marital status, and employment were control variables (confounders). Racial group membership was the effect modifier. Linear regression model was utilized to analyze the data. Results. Overall, higher education and income were associated with better SRH. Race showed significant statistical interactions with education and income on SRH, indicating weaker boosting effects of high education and income on SRH of non-Hispanic Blacks than non-Hispanic Whites. At least some of the diminished return of education on health for non-Hispanic Blacks than non-Hispanic Whites was due to income. Conclusions. While high education and income improve SRH of Californians, these effects are unequal between non-Hispanic Blacks and non-Hispanic Whites with education and income showing diminished health returns for non-Hispanic Blacks than non-Hispanic Whites. More than the availability of education and income, what populations can do with their education and income may be important. Under segregation, racism, and discrimination, education and income have weaker effects on changing the living condition of the historically oppressed racial group. To close the existing racial gap in health, we need much more than equalizing access to education and income. Education quality of urban public schools should be improved. Types of occupations that are available in Black communities should be improved. Meanwhile, non-Hispanic Black middle class should be helped so they can better leverage their SES resources and turn to outcomes. Such changes need a through change to the living conditions of non-Hispanic Blacks across all SES levels.