Objective: The American Board of Thoracic Surgery-certifying examination is challenging for applicants. Single institutions have reported good results with a mock oral examination (MOE) for trainees. General surgery literature has demonstrated success with in-person multi-institutional MOE examinations. Due to small numbers of cardiothoracic training programs and significant geographic variability, we hypothesized that a multi-institutional, collaborative remotely administered MOE (mICMO) pairing faculty with trainees from different institutions would provide an important educational experience. Methods: mICMOs were conducted via the Zoom virtual platform across 6 institutions. Descriptive results via post-experience survey were analyzed and reported. Results: In total, 100% of trainees found mICMO useful. The majority would recommend to a peer, and 100% of faculty examiners found mICMO useful and would participate in another examination. Conclusions: Faculty and trainees found the experience to be effective with respect to creating a high-stakes environment, educationally beneficial, and productive. These results support the continued use of mICMO and encourage expansion and collaboration with additional institutions across the country. (JTCVS Open 2020;3:128-35) Drs Antonoff and Fiedler examine a trainee during the pilot mICMO examination. CENTRAL MESSAGE mICMO is a collaborative effort across institutions to virtually simulate a high-stakes MOE of the ABTS qualifying examination to educate and prepare our trainees for board certification. PERSPECTIVE The ABTS-certifying examination is challenging for applicants. An MOE has been shown to improve trainees' performance. Creating a simulated, virtual, high-stakes MOE with trainees examined by faculty outside their home institution has not been investigated. We found that this multiinstitutional collaborative effort is useful and educationally beneficial. See Commentaries on pages 136 and 138. Successfully preparing for, taking, and passing The American Board of Thoracic Surgery (ABTS) certifying and qualifying examinations and becoming a board-certified cardiothoracic surgeon is a challenging endeavor and a major accomplishment for graduates of Accreditation Council for Graduate Medical Education (ACGME)-accredited cardiothoracic surgery training programs. 1-3 To become