Background: Precision medicine has revolutionized cancer care across multiple tumor types and new actionable biomarkers and targeted therapies are emerging at an unprecedented pace, creating myriad opportunities to optimize care and mitigate the often-dire sequelae of traditional cancer therapy. Many oncology healthcare professionals (HCPs) in practice are not employing optimal testing methodologies to detect biomarkers in patients who could benefit from novel targeted therapies. In this study, we analyze HCP awareness and application of RET alteration testing and integration of recently approved, new-generation selective RET inhibitors into practice for appropriate patients with NSCLC and thyroid cancer. Methods: In August 2020 HCPs were surveyed on RET alteration testing and use of RET-targeted therapeutics in their current practice. Study eligibility criteria included active HCPs in an oncology, pulmonology, or pathology practice. A curriculum of live and online educational activities was then developed for any interested oncologists and pathologists on RET alteration testing and/or targeted therapy for RET-altered lung and thyroid cancers. These activities included case studies, polling, and evaluations that provided additional insight on self-identified practice trends. In June 2021, at the completion of the educational program, eligible HCPs were surveyed again on RET alteration testing and selection of RET inhibitor therapy for appropriate patients. Results: In August 2020, 123 practicing HCPs completed the initial survey and 33% were testing patients for RET gene alterations and 18% were aware of the most sensitive testing assay for detection of RET fusions. 25% and 7%, respectively, were aware of the current indications for RET inhibitors in RET fusion–positive NSCLC and RET-altered thyroid cancer. Self-identified practice trends identified among the unselected cohort of 12,537 individual HPCs participating in the educational activities also demonstrated similar lack of appropriate testing for RET alterations and use of RET inhibitors. In June 2021, 60 practicing HCPs completed the follow-up survey and 40% were testing patients for RET gene alterations and 25% were aware of the most sensitive testing assay for detection of RET fusions. 52% and 22%, respectively, were aware of the current indications for RET inhibitors in RET fusion–positive NSCLC and RET-altered thyroid cancer. Conclusions: The rate of broad testing for RET alterations across patients with NSCLC and thyroid cancer remains low and many HCPs lack understanding of when to consider treating with a RET inhibitor. These results underscore the lag in adoption of optimal precision medicine approaches in oncology and the need for expert guidance and educational activities to optimize individualized, biomarker-driven treatment approaches for patients with cancer.