Little is known about HIV testing among bisexual men in the United States. Existing studies lack adequate representation, multivariate analytical strategies, and measurement of bisexuality indicators. To address these limitations, this study used the National Survey of Family Growth (N = 3,875). Sexual behavior and identity measures compared bisexual and other men along HIV testing history, reasons for testing, and recency of testing. Multivariate analyses adjusted for sociodemographic and risk factors that covary with testing. Bisexually active men were significantly less likely than homosexually active men to ever test, and they tested less often to know their HIV serostatuses. Bisexual identification decreased the odds of testing among bisexually active men but not others. Findings suggest that bisexual behavior and identity interact to decrease men's likelihoods of HIV testing. Interventions must recognize the potentially mediating roles of bisexual identity and behavior as well as risk factors that increase bisexual men's susceptibility to HIV infection.