Background: NCCN (National comprehensive Cancer network) recommends adjuvant chemotherapy for stage 3 colon cancer patients. National Cancer Data Base (NCDB) data were analyzed to investigate the impact of insurance status on receiving standard quality of care with adjuvant chemotherapy for stage 3 colon cancer patients. Methods: Data was analyzed from 11,563 men and women, between ages 18-80 years, registered in the NCDB who were diagnosed with stage 3 colon cancer between 1998 and 2011 and had follow-ups to end of 2012. The primary predictor variable was payer status and the outcome variable was treatment received. Additional variables addressed and adjusted for included sex, age, race, Charlson Comorbidity index, education, income, distance traveled facility type and diagnosing/treating facility. Results: Among these 11,563 patients, the mean age at diagnosis was 60.3 years (median, 61 years). The mean ages at diagnosis were 53.3, 54.9, 53.9, 69.6, and 58.2 years for uninsured, private, Medicaid, Medicare and unknown payer status, respectively. In multiple logistic regression analysis, after adjusting for secondary predictor variables, payer status was a statistically significant predictor of not receiving adjuvant chemotherapy. Relative to privately insured patients, patients with Medicaid were 2.20 times, Uninsured were 2.16 times, Medicare was 1.76 times, and unknown insurance were 2.25 times more likely not to receive adjuvant chemotherapy, respectively. Compared to age group 18-49 years, patient with age group 50-64 years, 65-74 years and 75+ years were 1.59, 2.54 and 5.59 times more likely to not to received adjuvant chemotherapy, respectively. Of the factors analyzed, age, comorbidity index, insurance and distance travelled to treatment center were statistically significant predictors of a patient not receiving adjuvant chemotherapy. Conclusions: We observed that payer status has a statistically significant relationship with stage 3 colon cancer patients not receiving adjuvant chemotherapy. This remained true after adjusting for other predictive factors. Further research is necessary to investigate how the treatment disparities are associated with different types of insurance.