Pre-exposure prophylaxis (PrEP), formulated as a once-daily pill, represents an effective form of biomedical HIV prevention for men who have sex with men (MSM), but its use among African American MSM remains suboptimal and low relative to White MSM. African American MSM are more likely to report suboptimal adherence and subsequently seroconvert while using PrEP. As such, the use of long-acting injectable (LAI) antiretroviral drug formulations as PrEP may be an attractive alternative for MSM interested in biomedical HIV prevention but who may have difficulties with daily pill-taking. However, little is known about what factors may influence willingness to use LAI-PrEP among African American MSM. The proposed research will leverage existing data from the N2 Study, a population-based longitudinal cohort of young HIV-negative African American MSM residing on the South Side of Chicago (n = 350). Using detailed information on the social and sexual networks of young African American MSM, we will assess whether ones willingness to use LAI-PrEP is impacted by their position within their networks. Using a complex systems approach known as agent-based modeling, we will simulate HIV transmission in the dynamic networks of young African American MSM, allowing us to assess the potential effects of a network-based intervention in improving LAI-PrEP use and reducing HIV incidence. Identifying the social dynamics associated with future use of LAI-PrEP may make a significant impact on the future success of this prevention method and the speed at which an effective LAI-PrEP formulation is taken up among young African American MSM. In achieving our aims, the findings from the proposed research may be used to optimize the uptake of LAI-PrEP through innovative network-based interventions, potentially maximizing its ability to make a sustained impact on the HIV epidemic in the United States.