Background: One crucial aspect of the Affordable Care Act is the optional Medicaid expansion, which started in 2014. Patients with testicular cancer may derive particular benefit from Medicaid expansion due to demographics overlap. We hypothesize that Medicaid expansion would improve outcome in these patients. Methods: We reviewed the Surveillance Epidemiology and End Results (SEER) database for testicular cancer diagnosed from 2010 to 2014. Among the SEER regions, we separated in to states that did (CA, CT, HI, IA, KY, MI, NJ, NM, WA) or did not (AK, GA, LA, UT) undertake expansion. Medicaid data from CMMS were used to measure the degree of Medicaid expansion (EXP). Data from 2010-2013 was used as baseline, and 2014 as the effect of EXP. Chi-square test was used to compare between groups. Results: We identified 12731 cases of testicular cancer from 2010 to 2014. Within SEER regions, overall Medicaid enrollment increased by 30.4% from 2013 to 2014 in the EXP states, and by 8.4% in non-EXP states. Expansion did not affect incidence of testicular cancer. In the EXP states, Medicaid coverage for testicular cancer increased from 14.8% to 19.4% in 2014 (p < 0.001) and uninsured decreased from 8.7% to 4.3% (p < 0.001). In non-EXP states, coverage with Medicaid (9.7% to 8.8%, p = 0.60) and uninsured (13.6% to 12.9%, p = 0.68) did not change. Within individual states, we noted a linear correlation between % increase in Medicaid enrollment and % decrease in uninsured cases (R = 0.58). Among Medicaid patients in EXP states, stage I cases increased (52% to 60%), stage III cases decreased (27% to 20%). There was no change among insured patients (70.6% to 73.3% for stage I, and 10.9% to 9.1% for stage III). In contrast, in non-EXP states, Medicaid patients had decrease in stage I and increase in stage III cases. Medicaid patients had higher rates of no treatment and lower rates of lymph node assessment for stage II NSGCT compared to insured patients, but this did not vary with EXP. Conclusions: Medicaid expansion reduced rate of uninsured for patients with new diagnosis of testicular cancer. There was a shift to earlier stage of diagnosis in Medicaid patients, but no apparent effect yet on management. Future studies will focus on change over time and effect on survival.