Background: It is unknown if staging and surveillance imaging in Stage I/II colon cancer are under- or over-utilized. On one hand, the Choosing Wisely campaign advocates against positron-emission tomography (PET) imaging and overzealous use of CT surveillance. Meanwhile, the NCCN recommends CT chest/abdomen/pelvis (CT C/A/P) at staging for Stage I/II colon cancer. For Stage II only, NCCN recommends surveillance CT C/A/P every 6-12 months for up to 5 years. Herein, we measure both underutilization and overutilization of staging and surveillance imaging in Stage I/II colon cancer. Methods: Insurance claims data from 2008-2016 were queried using OptumLabs (Cambridge, MA) for Stage I/II adult colon cancer patients who underwent surgery alone. Utilization of PET and CT C/A/P imaging was evaluated both during initial staging (N = 6,291) and surveillance for patients with at least 1 year of follow up (N = 5,466). Over-utilization was defined as (1) any usage of PET during staging or surveillance or (2) > 2 CT A/P or PET scans per year during surveillance. Results: Overall, 31% of Stage I/II colon cancer patients did not receive a staging CT A/P and 95% did not receive a CT chest on diagnosis. However, rates of staging CT A/P increased from 62% (2008) to 75% (2016) and rates of CT chest rose from 2.3% (2008) to 7.1% (2016). Use of PET imaging also increased slightly from 5.2% (2008) to 6.5% (2016) despite guidelines recommending against its use. On surveillance, 30% of patients with at least 1 year of follow up received a CT A/P or PET within the first year of surveillance. This dropped to 18% in year 2, 9% in year 3, 6% in year 4, and 3% in year 5 of follow up. Of patients who had surveillance CT A/P or PET, the proportion receiving > 2 scans within the first year (representing overutilization) declined from 32% (2008) to 10% (2016), p = 0.01. Conclusions: A large proportion of Stage I/II colon cancer patients do not receive appropriate staging CTs at diagnosis; however, the utilization of PET imaging at staging remains appropriately low. Furthermore, the vast majority of patients undergoing surveillance do not even receive 3 years of imaging follow-up. Among those who do receive surveillance imaging, overutilization has declined over time.