Project Abstract Anal cancer risk is 80-fold higher among men who have sex with men (MSM) living with HIV compared to the general population, making MSM a critical population for implementing evidence-based anal cancer prevention interventions. A randomized controlled trial at 21 clinical sites in the United States of people living with HIV, recently established treatment of high-grade squamous intraepithelial lesions (HSIL) as an evidence-based intervention (EBI) for anal cancer prevention. Given its established efficacy, HSIL screening and treatment should be implemented as prophylactic care to prevent anal cancer in low- and middle-income country (LMIC) settings where HIV is highly prevalent. To accelerate adoption of HSIL screening and treatment in LMIC settings, we will leverage an existing HIV infrastructure, the TRUST clinic, an MSM-friendly facility in Nigeria that has been providing HIV care to a cohort of MSM since 2012. We conducted a proof-of-concept anal cancer screening and treatment study at the TRUST clinic and found high uptake in the MSM community; representativeness, as those screened had similar prevalence of HIV and high-risk human papillomavirus as our overall cohort; and overall patient satisfaction. Despite high screening volumes, we under-detected and under-treated HSIL. Knowledge gaps in HSIL screening and treatment among both the care team and the participants were identified as major barriers that impeded implementation of the EBI with fidelity. The objective of the proposed Integrated Model for the Prevention of Anal Cancer using screen and Treat for HSIL (IMPACT) study is to address these barriers while capitalizing on facilitators within the existing TRUST clinic infrastructure to create an enhanced training on Screening and Treatment of HSIL (e-STH) intervention. To achieve this goal, in AIM 1, we will use the Consolidated Framework for Implementation Research (CFIR) and mixed methods to identify barriers and facilitators to usual training on the EBI at the TRUST clinic. In AIM 2, we will engage an implementation team to co-design the e-STH intervention by matching the barriers identified with CFIR with specific strategies in the Expert Recommendations for Implementing Change (ERIC) framework. We will then take an iterative improvement approach to test and refine the implementation of the e-STH intervention based on specific outcomes. In AIM 3, we will conduct a prospective study to evaluate the reach, efficacy, and implementation and explore the sustainability of e-STH compared to usual training using the RE-AIM framework. The proposed IMPACT study will provide insight into implementation of an HSIL screening and treatment EBI adapted for existing community-based HIV clinics in Nigeria and generate essential evidence for scalability across LMICs.