Lost in the debate over the use of racial and ethnic categories in biomedical research is community-level analysis of how these categories function and influence health. Such analysis offers a powerful critique of national and transnational categories usually used in biomedical research such as “African-American” and “Native American.” Ethnographic research on local African-American and Native American communities in Oklahoma shows the importance of community-level analysis. Local (“intracommunity”) health practices tend to be shared by members of an everyday interactional community without regard to racial or ethnic identity. Externally created (“extra-community”) practices tend to be based on the existence of externally-imposed racial or ethnic identities, but African-American and Native American community members show similar patterns in their use of extra-community practices. Thus, membership in an interactional community seems more important than externallyimposed racial or ethnic identity in determining local health practices, while class may be as or more important in accounting for extra-community practices.