In 2019, the U.S. Advisory Committee on Immunization Practices recommended shared clinical decision-making (SCDM) for HPV vaccination among unvaccinated adults aged 27–45 years (i.e., mid-adult). However, the implementation of this recommendation is challenging. This study assessed a decision tool, HPV Decide, designed to facilitate SCDM for mid-adult HPV vaccination. We used exploratory sequential mixed methods to gather stak...