137 Background: The treatment armamentarium for patients with metastatic colorectal cancer (mCRC) has expanded significantly and treatment options for progressive disease remain limited. As data from clinical trials or subgroup analyses become available, landmark trials are published, and guideline recommendations or clinical utility of these therapies change, continuing medical education (CME) for oncologists is necessary to ensure that eligible patients continue to receive effective therapies. Methods: A series of 7 activities launched from 2016-2020 to reach a global oncology audience in the care of patients with mCRC. The educational activities included multi-modality approaches with didactics, cases, simulations, and panel discussions. Educational effectiveness was assessed with repeated paired pre/post assessment where learners served as their own controls to measure changes in knowledge, competence, confidence, and performance. Oncologists who completed both the pre- and post-CME questions or who made relevant clinical decisions in the simulation activity were included in analysis and McNemar’s tests were conducted to assess statistical significance of the results with p < .05 being considered significant. The first activity launched on 6/8/2016 and the data reported were collected through 7/20/20. Results: As of 7/20/2020, 59,595 learners participated in the activities, including 18,634 total physician learners with 5,862 oncologists. Significant improvements in knowledge, competence, and confidence among oncologists, measured as relative % changes in correct responses or confidence from pre- to post-CME, were seen (n=60-214) [% pre, % post, p value]: 11%: knowledge regarding therapies for progressive disease in mCRC (83; 92; p < .05); 17%: knowledge of clinical trials assessing impact of patient/disease specific aspects on treatment selection (63; 74; p < .001); 11%: competence selecting therapy (55; 61; p < .05); 41%: confidence selecting therapy (34; 48; p < .001); 24%: confidence addressing communication barriers in mCRC (50; 62; p < .01). Significant improvement in performance of oncologists, measured as absolute % changes in pre- to post-CME correct responses were seen (n = 46) [% pre, % post, p value]: 28%: starting preferred treatment options (24; 52; p < .01); 18%: prescribing regorafenib (24; 43; p < .01); 9%: prescribing trifluridine + tipiracil (0; 9; p < .05). Conclusions: This series of online, expert-led, CME-certified educational activities resulted in significant improvement in knowledge, competence, confidence, and performance among learners regarding the management of patients with progressive metastatic colorectal cancer over time. These results demonstrate the effectiveness of on-demand education as new data emerge and indications expand to reinforce existing knowledge, close persistent gaps, and increase confidence in managing these patients.