Version 9 of the American Joint Committee on Cancer (AJCC) Cancer Staging System for Oropharynx (HPV-Associated). The new Version 9 Oropharynx (HPV-Associated) content is presented in a streamlined, easy-to-use format, incorporates the World Health Organization (WHO) Classification of Tumors histology codes. Physicians, registrars, researchers, and other content users will benefit from the updated content, including tables, explanatory notes and illustrations. Version 9 of the Oropharynx (HPV-Associated) Cancer Staging System becomes effective on January 1, 2026 and replaces the 8th Edition HPV-Mediated (p16+) Oropharyngeal cancer site content.