Context: Vaccine delivery services on a local, clinical level should constantly be assessed to minimize missed opportunities in vaccine administration. Objective: We conducted a mixed-methods study to identify quality improvement targets for adolescent HPV vaccination within a pediatric primary care clinic. We sought to: (1) develop a process map to describe adolescent clinical vaccination processes, (2) identify gaps in the delivery of adolescent vaccines, and (3) track adolescent vaccination opportunities to identify and compare trends in adolescent vaccination delivery of HPV, Tdap, and meningococcal vaccines. Setting/Study design/Population studied: We conducted key-informant interviews with providers, nurses, medical assistants, and front desk staff at a pediatric primary care outpatient clinic. Interview topics included participants’ roles within the clinic, HPV vaccination processes, vaccination documentation, and patient hand-offs between clinical team members. Findings were translated into a process map illustrating patient flow, provider and staff roles in vaccination, and gaps in service delivery. Retrospective chart review was conducted using quality improvement reports of vaccine administration extracted from the electronic health record for patients who were due for a vaccine (HPV, Tdap, Meningococcal) from 1/1/2019 to 12/31/2019. All non-sick visits were included for patients 11 to 19 years old who were eligible to receive the vaccine. We will compare rates of opportunities taken in HPV vaccine administration to Tdap and meningococcal vaccines. We will compare rates of opportunities taken in HPV vaccine administration by gender, age group, provider type, and visit type. Preliminary results: One front staff, two medical assistants, one charge nurse, one pediatric resident and two attending physicians were interviewed. Responses were organized into a process map. Notable gaps included EHR glitches (records not documented in the EHR, missed pre-charting, follow up visits not scheduled) and provider concerns (staff believing HPV is ‘optional’ or provider not knowing the schedule). HPV vaccine had lower rates in opportunities taken compared to Tdap and Meningococcal rates. Next steps of the project are to use the gaps identified from the qualitative work (process map) to improve communication between the EHR and state vaccine registry and improve staff as well as provider education about HPV importance and schedule.