6512 Background: Income eligibility limits for Medicaid, the health insurance programs for low-income populations in the United States, vary substantially by state for the non-elderly population. This study examined associations between state Medicaid income eligibility limits and long-term survival among newly diagnosed cancer patients. Methods: 1,426,657 adults aged 18-64 years newly diagnosed with 17 common cancers between 2010 to 2013 were identified from the National Cancer Database. States’ Medicaid income eligibility limits were categorized as < = 50%, 51%-137%, and > = 138% of Federal Poverty Level (FPL). Survival time was measured from diagnosis date through December 31, 2017, for up to 8 years of follow-up. Multivariable Cox proportional hazard models with age as time scale were used to assess associations of eligibility limits and stage-specific survival, controlling for age group, sex, race/ethnicity, metropolitan statistical area, number of health conditions other than cancer, year of diagnosis, facility type, and the random effect of state of residence. Results: Among newly diagnosed cancer patients aged 18-64 years, 22.0%, 43.5%, and 34.5% resided in states with Medicaid income eligibility limits ≤50%, 51%-137%, and ≥138% FPL, respectively. Compared to patients living in states with Medicaid income eligibility limits ≥138% FPL, patients living in states with Medicaid income eligibility limits ≤50% and 51-137% FPL were more likely to have worse survival for most cancers in both early and late stage. The highest hazard ratios (HRs) were observed among patients living in states eligibility limits ≤50% FPL (p trend < 0.05). For example, for early stage female breast cancer patients, the HRs were 1.31 (95% confidence interval [95% CI]: 1.18 – 1.46) and 1.17 (95% CI: 1.06 – 1.30) for patients living in states with Medicaid income eligibility limits ≤50% and 51%-137% compared to those living in states with Medicaid income eligibility limits ≥138% FPL. Conclusions: Lower Medicaid income eligibility limits were associated with worse long-term survival within stage, with variation below the Medicaid eligibility threshold as part of the Affordable Care Act. States that have not expanded Medicaid income eligibility limits should expand them to help improve survival among cancer patients.