Human immunodeficiency virus (HIV) prevention interventions, such as preexposure prophylaxis (PrEP), are often targeted to men who have sex with men (MSM) who self-report high-risk behaviors. Data from a prospective study evaluating methods to detect acute HIV infection among a primarily young (aged <25 years) and black or African American (African American) population from North Carolina were analyzed. In the study, participants were asked about risk behaviors during pretest counseling (at the time of testing) and then during a partner services interview (at HIV diagnosis). Participants whose disclosure of sexual risk behaviors during pretest counseling was different from their disclosure of sexual risk behaviors during their partner services interview were identified, and factors associated with these discordant responses were examined. Among 113 HIV-infected men, 26 (23.0%) did not disclose male sex partners at pretest counseling, but subsequently did disclose this information during their partner services interview. When compared with men who disclosed having male partners at pretest counseling, these 26 MSM who did not disclose male partners during pretest counseling were found to have a similar number of male partners during contact tracing, but were more likely to have a female partner (30.8% versus 6.9%). In addition, the proportions of MSM found to have at least one HIV-infected partner were similar for both groups (MSM who disclosed having male partners during pretest counseling and those who did not). To better customize HIV prevention interventions for MSM, HIV prevention programs might consider using novel strategies to accurately assess risk in this population.