Project Summary Young men who have sex with men (YMSM)—ages 13 to 24 years old—are a priority population for HIV prevention, as they represented nearly a quarter of all new HIV cases among men who have sex with men in the United States in 2021. Moreover, YMSM represented 20% of new HIV cases in nonmetropolitan areas, which is relevant given the focus on rural communities in the federal Ending the HIV Epidemic (EHE) plan. One highly effective option for HIV prevention is Pre-Exposure Prophylaxis (PrEP). Still, PrEP use remains low among YMSM, and for those who do take it, adherence to oral PrEP is often suboptimal. The recent United States Food and Drug Administration’s approval of long-acting injectable (LAI) PrEP, cabotegravir, holds promise to increase PrEP use and improve adherence. However, our understanding of PrEP preferences and implementation needs for rural YMSM remains limited as the literature has primarily focused on older rural samples or younger urban and national samples; more research is needed among rural YMSM to determine how newly available LAI PrEP can be implemented for this population. Implementation science frameworks can guide research into understanding factors influencing implementation of evidence-based practices like LAI PrEP. As such, I propose a convergent mixed methods study to identify rural YMSM’s LAI PrEP preferences and implementation needs informed by the Consolidated Framework for Implementation Research (CFIR). We will conduct in-depth virtual interviews with rural YMSM (n = 35)—residing in a rural area within one of the seven states with rural HIV burden listed in the EHE plan—to identify perceptions of LAI PrEP and acceptability of various PrEP delivery models using reflexive thematic analysis (i.e., Aim 1). Concurrently, an online survey will be fielded in the seven EHE states with rural HIV burden to identify groups of rural YMSM (n = 300) with distinct PrEP modality preferences using latent profile analysis and exploring predictors of profile membership (i.e., Aim 2). Finally, data from Aims 1 and 2 will be used for mixed methods integration data analysis to identify implementation strategies, which will then be positively vetted by rural healthcare providers through empowered deliberation (i.e., Aim 3). These identified strategies will be pilot tested in future research led by the candidate. The training plan of this F31 award is designed to support Mr. Andrew M. O’Neil—an underrepresented candidate—with foundational experience to support his development into an independent investigator. The candidate will gain (1) foundational content and methodological expertise in implementation science research in the field of HIV prevention, (2) competency in advanced quantitative data analyses, (3) necessary skills in mixed-methods research and analysis, (4) training in responsible and ethical conduct in research, and (5) individually-tailored professional development to support transition into a research-focused ...