Prevalence of developmental disabilities among the three largest U.S. racial and ethnic groups was estimated. Groups were compared on household economic status and access to welfare programs. Secondary analyses were conducted on 1990 and 1991 panels of the Survey of Income and Program Participation, a nationally representative data base of the demographic and economic status of U.S. households. Estimated prevalence rate was 1.1% (June through December 1991), with the highest rate (1.4%) among Blacks. Households with a family member with developmental disabilities had significantly lower income and greater dependence on means-tested income support. Minority status exacerbated differences in earned income and access to welfare. Results were discussed in the context of general U.S. demographic trends.