Genetic ancestry tests have been used to verify or dispute family stories about ancestors, to seek belonging with a particular tribe or community, and to identify genetic variants across populations in medical research. But assumptions about genetic testing – and the very idea of a “genetic” identity – pose challenges for communities defined in terms of political, social, and cultural identities. Nanibaa’ A. Garrison explores the potential implications of ancestry tests for Native American tribes and communities and concludes that, while their scientific and recreational use continues to increase, limitations of consistency across platforms and the generalizability of knowledge remain.