Background: In a quest to tailor care to tumor biology, oncologists now offer germline testing to all patients with APC. We explored the degree to which germline testing decisions reflect patient preferences about potential benefits and harms discussed by oncologists. Methods: We conducted a prospective qualitative study of consecutive patients with APC who were offered germline testing at an oncology visit at the San Francisco VA. We audio-recorded visits and conducted semi-structured interviews using a theory-informed guide with patients after their visit to understand their decision-making process for germline testing. We analyzed the interviews using the Critical Incident Technique to identify positive or negative deviations from well-informed, preference-based decisions. We also reviewed consent documentation in the electronic health record. Results: Of 61 patients approached, 30 completed interviews after their germline testing discussion. Mean age was 75y; 19 (63%) were White, 9 (30%) Black, and 2 (6%) Other race; and 13 (43%) were service-connected for APC. Twenty-six (87%) patients consented to germline testing; the primary reasons were altruistic (to help family and contribute to knowledge). Four patients (13%) declined testing, all primarily due to the fear of potential loss or reduction of service-connected benefits. All four patients reported they would reconsider testing if assured that these benefits would be protected regardless of test results. Of the four patients, two had initially consented to testing with their oncologist but later changed their minds and did not notify anyone. The two patients received germline testing when they underwent PSA testing, but they were not aware that they had germline testing performed. Both had negative test results, and they therefore did not experience threats to their service-connected benefits. Conclusions: Some Veterans with service-connected benefits for APC decline germline testing due to the fear of potential loss or reduction of these benefits, thereby foregoing potential treatment benefits. An advisory board is working with the Veterans Benefits Administration to protect service-connected benefits for these Veterans. In addition, a few Veterans may agree to germline testing with their oncologist, but then change their minds due to concerns surrounding service-connected benefits. From a quality improvement perspective, the experiences of the patients in this study who changed their minds counts as a near-miss. Although uptake of germline testing was high in this cohort, current workflows may need to be addressed to account for a change of heart, and further research is needed to understand root causes and identify possible remedies of the near-misses. Overall, our findings illustrate the importance of informed consent for germline testing to ensure that results are desired and valued by both oncologist and patient.