28 Background: Genetic counseling and germline testing have an increasingly important role for patients with prostate cancer, with the recent approval of precision therapeutic options and implications for cancer screening in families. Although current guidelines recommend germline genetic evaluation for all men with metastatic prostate cancer and some with localized disease, recent data suggests it is underutilized. Our objective was to perform a qualitative study of barriers and facilitators of genetic counseling and germline genetic testing among physicians who manage prostate cancer. Methods: We conducted semi-structured interviews with medical oncologists, radiation oncologists, and urologists from different U.S. practice settings until thematic saturation was achieved at n = 14. The interview guide was based on the Tailored Implementation in Chronic Diseases Framework to identify key determinants of practice. Interview transcripts were independently coded by ≥2 investigators using a constant comparative method. Disagreements were resolved by team discussion. NVivo12 was used for data organization and analysis. Results: The decision to perform or refer for germline genetic evaluation is affected by factors at multiple levels (Table). Although patient factors play a role in some cases (e.g., refusal of testing for specific reasons), the dominant themes in the decision to conduct germline genetic evaluation were primarily at the physician and organizational level. Physician knowledge of prostate cancer genetics, coordination of care between providers, perceptions of the guidelines for genetic testing, and concerns about cost were most frequently discussed as the main factors affecting utilization of germline genetic evaluation. Conclusions: There are currently numerous barriers to the performance of germline genetic evaluation for prostate cancer. Efforts to expand physician education and to facilitate coordination of care surrounding genetic evaluation are important to promote guideline-concordant care. [Table: see text]