439 Background: Genomic tumor testing (GTT) impacts how clinicians evaluate and treat cancers, yet there remain barriers to effective implementation of GTT in the clinical setting, particularly in resource constrained practices. S2108CD is a cluster randomized trial comparing an educationally enhanced genomic tumor board intervention to usual practice to increase evidence-based genome-informed therapy. We use a mixed-methods approach to assess the baseline utilization of GTT and genomic confidence of physicians practicing at rural and community oncology clinics. Methods: Physicians at sites enrolled on S2108CD completed baseline questionnaires collecting demographics, practice characteristics, and genomic confidence using a validated measure. Of the physicians registered within 6 months of study activation, we conducted semi-structured interviews with select physicians in both arms to understand GTT utilization at baseline. Descriptive statistics were generated for survey data. Interviews were analyzed using conventional content analysis to identify recurring themes. Results: Between 8/2022-2/2023, 50 physicians were included in the analysis from 10 Recruitment Centers, with 25 physicians from each arm. Registered physicians were predominantly male (82%), white (66%), and non-Hispanic (94%); 29 (58%) were board certified in hematology and medical oncology, 15 (30%) in medical oncology, and 5 (10%) in gynecologic oncology. Nearly half (48%) were within 20 years of graduation from medical school. More than half (56%) reported formal training in the use of genomic testing. 49 physicians (98%) completed the survey. In their ability to determine clinical appropriateness of GTT, 27 (55%) physicians felt very confident, 19 (39%) moderately confident, and 3 (6%) a little confident. In their ability to use GTT results for clinical decision-making, 23 (47%) felt very confident, 25 (51%) moderately confident, and 1 (2%) a little confident. In their ability to explain GTT to patients, 28 (57%) physicians felt very confident, 19 (39%) moderately confident, and 2 (4%) a little confident. Five physicians from each arm were interviewed. The interview data confirmed that physicians felt confident with GTT, particularly with identifying when and which GTT to send. While physicians expressed confidence in interpreting genomic results with FDA-approved targeted agents, some expressed lower confidence in decision-making for genome-informed therapy when data is less robust. Conclusions: Physicians enrolled on S2108CD self-reported high genomic confidence at baseline. Based on interview data, there remains a need for resources to assist in interpretation of pathogenicity of genomic variants and utility of genomic-targeted therapies in non-FDA approved indications. Funding: NIH/NCI/NCORP grant UG1CA189974. Clinical trial information: NCT05455606 .