Biomedical advances in diagnostics, treatment and prevention increase the means available to reduce HIV transmission risk. Subsequent shifts in HIV status disclosure obligation and ethics may impact how those living with HIV view, enact and experience disclosure. We analysed focus group and interview data to explore how these changes are reflected in disclosure decision-making to sexual partners among young gay and bisexual men living with HIV in the USA. Three interrelated themes were identified: engaging with partners’ varying HIV knowledge; attribution of blame; and negotiating disclosure-related harms. Participants experienced blame from partners that questioned the timing of HIV testing, status disclosure and sex events without regards for viral suppression or use of pre-exposure prophylaxis. Substantial HIV stigma was described in response to disclosure, mitigated in some cases by partners’ higher HIV knowledge. Overall, an uneven diffusion of HIV treatment and prevention knowledge and continuing HIV stigma seemed to limit the translation of biomedical advances into improved disclosure experiences. Our findings suggest that young gay and bisexual men living with HIV may continue to perform much of the moral labour involved in disclosure by managing others’ reactions, correcting inaccurate sexual health information, and negotiating the risks of disclosure-related harm.