To meet lofty human papillomavirus (HPV) immunization goals in Tanzania, the Ministry of Health integrated HPV vaccination with adolescent health services using a school-based approach. A qualitative study was conducted in June–July 2021, examining the feasibility and sustainability of an integrated service package, HPV Plus. In-depth interviews with 46 program implementers (i.e., healthcare workers, teachers) and planning stakeholders (i.e., government officials, school administrators) in Dar es Salaam and Njombe Regions explored enablers and constraints to HPV Plus program implementation, including resource and staffing requirements. Two facilitators and three barriers to HPV Plus feasibility and sustainability were identified from thematic analysis of interviews. Interviewed stakeholders emphasized the program’s feasibility, especially if the efficiencies offered by a school-based platform were optimized. Implementation facilitators included: (1) optimized service delivery efficiency through a school-based platform and (2) resources saved by combining adolescent health services and HPV immunization into a single program package. Key barriers to HPV Plus feasibility and sustainability were: (1) time, space, and resource constraints (e.g., commodity stockouts, challenges delivering the complete service package to large cohorts of students within allotted times); (2) human resource gaps and increased workloads within the health workforce; and (3) insufficient referral mechanisms linking schools to health facilities. Scaling up HPV Plus will require proactive commodity procurement and security; resource mobilization to reach ambitious service delivery targets; and close coordination of program implementation with school administrators.