Access to biomedical HIV prevention technologies such as pre-exposure prophylaxis (PrEP) requires individuals to disclose risk behavior to clinicians, but experiences of discrimination and medical mistrust may limit disclosure among male sex workers and other MSM. We explored experiences of perceived discrimination, medical mistrust, and behavior disclosure among male sex workers compared to other men who have sex with men (MSM). We conducted 56 interviews with MSM and compared findings about medical mistrust, discrimination, and disclosure for 31 men who engaged in sex work vs. 25 men who did not. MSM who engaged in sex work reported more medical mistrust and healthcare discrimination due to issues beyond MSM behavior/identity (e.g., homelessness, substance use, poverty). MSM who did not report sex work described disclosing sex with men to clinicians more often. Both subgroups reported low PrEP awareness, but willingness to disclose behavior to obtain PrEP. Medical mistrust and perceived discrimination create barriers for sexual behavior disclosure to clinicians, potentially impeding access to PrEP and other forms of biomedical HIV prevention. These barriers may be higher among male sex workers compared to other MSM, given overlapping stigmas including sex work, substance use, homelessness, and poverty. An intersectionality framework for understanding multiple stigmas can help to identify how these dynamics may limit access to biomedical HIV prevention among male sex workers, as well as suggesting strategies for addressing stigmas to improve the delivery of PrEP and other HIV prevention approaches in this population.