This article examines the relationship between cultural affiliation and deaf adults' motivations for genetic testing for deafness in the first prospective, longitudinal study to examine the impact of genetic counseling and genetic testing on deaf adults and the deaf community. Participants (n = 256), classified as affiliating with hearing, Deaf, or both communities, rated interest in testing for 21 reasons covering 5 life domains. Findings suggest strong interest in testing to learn why they are deaf, but little interest in using it for decisions about a partner or having children. Culturally mediated variation was also demonstrated. Deaf and both communities groups viewed testing as useful for more life domains than the hearing community group. Deaf and both communities had similar motivations related to further exploration, understanding, or strengthening of deafness. Motivations related to "hearing" were also relevant for both communities. We conclude that cultural affiliation is an important factor for constructing motivations for genetic testing.