Purpose To compare one-year outcomes and costs between severely obese Medicaid and non-Medicaid patients who underwent laparoscopic Roux-en-Y gastric bypass surgery. Methods Single institution, retrospective review comparing 33 Medicaid patients to 99 randomly selected non-Medicaid patients (1:3 case-control). 90-day and one-year outcomes were extracted from the electronic health record. Costs were obtained from the UW information technology division. Bivariate analyses were used to compare study variables. Results Emergency department visits (48.2% vs. 27.4%; p=0.06) and readmissions (37.0% vs. 14.7%; p=0.01) were more common for Medicaid patients. Medicaid patients had less excess body weight loss (50.7% vs. 65.6%; p=0.001) but similar comorbidity resolution and complication rates. One-year median costs were similar between Medicaid and non-Medicaid patients ($21,160 vs. $24,215; p=0.92). Conclusion One-year comorbidity resolution, complications and costs following laparoscopic Roux-en-Y gastric bypass were similar between Medicaid and non-Medicaid patients. Focusing on reducing ED presentations and readmissions would be a high impact area for future quality improvement initiatives.