Project Summary South Africa is home to over 7.9 million people living with HIV, the largest of any country globally. One significant barrier to ending the HIV epidemic is engaging and retaining men in care throughout the HIV care continuum. At each step, men are less likely than women to be engaged in care. Hegemonic masculinity, or idealized forms of what it means to ‘be a man,’ is documented as a major reason why men do not seek and stay engaged in care. Hegemonic masculinity in South Africa involves risk-taking, self-reliance, being sexually desirable, physical strength and health, having emotional control, and being an economic provider. Although these traits may be protective for men under certain circumstances, they are also inconsistent with seeking HIV care, which requires vulnerability, experiencing emotions traditionally viewed as more feminine (e.g., sadness), and invoking a relational dimension (as opposed to self-reliance). Further, the extent to which men internalize hegemonic masculinity, called hegemonic masculinity beliefs (HMBs), makes disclosure of their HIV status challenging for the same reasons; yet, disclosure is often the avenue through which men gain the necessary social support needed to seek and be retained in HIV treatment. In this mixed-methods study, we use Connell’s definition of hegemonic masculinity and the Disclosure Process Model to examine modifiable mechanisms that link HMBs to antiretroviral therapy (ART) initiation in newly-diagnosed men living with HIV (MLWH) in Cape Town, South Africa. We propose to do the following: (1) Examine whether disclosure mediates the association between HMBs and ART initiation, such that stronger HMBs will be associated with a decreased likelihood of HIV disclosure, which in turn will be associated with a decreased likelihood of ART initiation. We will also examine whether internalized stigma moderates the association between HMBs and disclosure, such that the negative association between HMBs and disclosure will be stronger in the context of high internalized stigma. We will recruit newly-diagnosed MLWH (N = 220) and assess HMBs within two weeks of testing positive and then again 3 and 6 months later. Data on ART initiation will be assessed at the 6-month assessment via chart review. (2) Examine whether, and how, the process of disclosure shifts men’s views of their own masculinity. We predict that men who disclose their HIV status during the study will experience a decrease in HMBs at the 6-month assessment, because theoretically disclosure as a behavior is inconsistent with HMBs. A subset of men who disclose their HIV status (n = 10) and those who do not disclose (n = 10) will be randomly selected to participate in a qualitative individual interview to further explain if, and how, disclosure led to a shift in HMBs. This proposed study is in line with the NIH Office of AIDS Research’s cross-cutting research priority on behavioral sciences focused on individual and interpersona...