Background/Objective: The aim of this study was to determine the prevalence of high-risk (HR) human papillomavirus (HPV) types by HPV vaccination status and the feasibility of using HPV L1 serology to identify HIV-negative men who have sex with men (MSM) who may be at risk for anal cancer. Methods: This cross-sectional study recruited HIV-negative MSM from a US metropolitan area. The prevalence of HR, quadrivalent, and nonavalent anorectal HPV DNA and HPV L1 serum antibodies was …