BACKGROUND: This study evaluates the implementation of the GETSET (Guiding Endocrine Therapy Success through Empowerment and Teamwork) pilot, a motivational interviewing (MI) intervention aimed at improving endocrine therapy (ET) adherence among patients with breast cancer. METHODS: Using the Consolidated Framework for Implementation Research (CFIR), qualitative interviews were conducted with site staff (N = 2), patients (N = 4), and counselors (N = 2). RESULTS: The thematic analysis identified facilitators such as high-quality materials, ease of scheduling sessions, and effective communication among staff. However, barriers included lack of personalization and systemic issues like understaffing. CONCLUSIONS: The study underscores the need to adapt implementation of behavioral interventions in a healthcare setting to improve ET adherence. As this was a process evaluation of a pilot study, future work should evaluate the barriers and facilitators to a larger clinical trial to identify if the same strategies should be refined.