Background: Standard adjuvant chemotherapy for Stage III colon cancer comprises FOLFOX (5 FU/oxaliplatin(OX)/leucovorin) or CAPOX (capecitabine (CAP), OX) for six months. Toxicity from OX impacts quality of life and persists beyond treatment. In March 2018, the NEJM published the IDEA study demonstrating that 3 month FOLFOX or CAPOX was non-inferior to 6 month with less toxicity, specifically in low risk (LR) populations ( < T4 and/or < N2). National guidelines then incorporated 3 month options. We profiled adoption of these regimens at NY Cancer & Blood Specialists after updated guidelines were published. By examining guideline compliance we hope to improve the treatment of patients with Stage III. Methods: We retrospectively reviewed all 234 electronic charts of patients presenting for management of Stage III after the NEJM publication. Substage, duration of therapy, and reasons for delay or discontinuation were analyzed. Results: 234 patients underwent surgery and presented for consideration of adjuvant therapy. 32 (14%) had stage IIIA, 164 (70%) had IIIB, and 32 (14%) had IIIC. 96 (41%) had high risk (HR) disease, 11/96 (11%) patients were recommended 3 months of therapy and 81/96 (84%) were recommended 6 months. 138 patients (59%) were LR, of which 48/138 (35%) were recommended 3 months of therapy and 81/138 (59%) were recommended 6 months. Thus, 59/234 (25%) patients were recommended to proceed with only 3 months of therapy (see table). 215/234 patients (92%) received adjuvant therapy (2 died prior to treatment start, 8 were not treated due to age or poor performance status, 1 had financial issues, 6 refused, 2 were lost to follow-up). 57 patients received or were planned for CAPOX, 114 for FOLFOX, 41 for CAP, and 9 for 5-FU. Treatment started a mean of 7 weeks post-op. 108/215 patients (50%) required dose interruptions, while 85 (40%) required dose reductions and 14 (7%) switched regimens. 164 patients (76%) completed the full duration with some therapy. 41 patients had a recurrence/progression (34 actually received adjuvant therapy). Conclusions: Among 234 patients with stage III colon cancer intended for adjuvant therapy in a large community practice, 25% were planned for or treated with 3 months vs 6. Of those that initiated therapy, 76% completed treatment. The results of the IDEA trial have influenced decision making for community oncologists. While only a quarter implemented shorter durations of treatment, we expect that this rate will increase as improved patient outcomes are demonstrated.