Background: Seminoma is the most common testicular cancer, and cancer specific survival approaches 100% if diagnosed and treated early. Following orchiectomy, several adjuvant therapy options exist for patients with stage 1A/B and 2A/B disease. As the Affordable Care Act’s (ACA) individual insurance mandate and expansion of Medicaid coverage will begin in 2014, we sought to understand whether differences exist in receipt of adjuvant therapy between uninsured and Medicaid patients in order to predict possible treatment patterns after the ACA takes effect. Methods: Uninsured and Medicaid patients diagnosed with seminoma from 1998-2010 in the National Cancer Data Base were identified. Multivariate logistic regressions were used to assess the relationship between uninsured status vs. Medicaid and receipt of adjuvant therapy. Results: Of 41,745 seminoma patients, 5,895 (14%) patients were on Medicaid or uninsured. Compared to Medicaid patients, uninsured patients were more likely to be younger (<29 years old), Hispanic, live in the South, treated in community hospitals, reside in areas with higher education levels, and present with stage IA/B disease (66.5% vs 59.4%, p < 0.01). After controlling for sociodemographic and clinical characteristics, uninsured stage IA/B patients had a 16% decreased likelihood of receiving adjuvant radiation or chemotherapy than Medicaid patients (p<0.05). In addition, stage 1A/B patients who were Hispanic, aged 50 or more, diagnosed in 2006-2010, treated in low-volume-case facilities or had tumor size < 4cm were less likely to receive adjuvant therapy. No treatment differences by insurance were seen in stage IIA/B patients. Conclusions: Our analysis suggests a modest association between the decision to seek optional adjuvant therapy and uninsured vs. Medicaid status in patients with stage IA/B seminoma. Given that national recommendations support surveillance, it will be increasingly important to counsel newly insured patients on the benefits of post-orchiectomy surveillance for early stage disease. In addition, no difference in management was identified for CS 2A/B patients suggesting that required therapy was not modified or avoided in the uninsured.