Ultra-processed foods (UPFs) account for over half of the caloric intake in the U.S. and are linked to heightened cardiometabolic risk. Participants in the Supplemental Nutrition Assistance Program (SNAP) consume a significant amount of UPFs, exacerbating dietary disparities. This study evaluates the health impacts of restricting UPF purchases in SNAP using dietary data from the National Health and Nutrition Examination Survey from 2007 to 2020. A Monte Carlo policy modeling framework was employed to simulate three scenarios, where 25%, 50%, and 100% of UPFs are replaced with minimally processed foods. The analysis found that replacing 100% of UPFs among SNAP participants resulted in reductions of 257 mg/day in sodium and 30.7 g/day in added sugars, alongside a gain of 1.13 g/day in fiber. These changes are projected to decrease systolic blood pressure by 0.64 mm Hg, reduce type 2 diabetes risk by 0.25%, and lower cardiovascular disease risk by 1.01%. Nonparticipants showed slightly larger health improvements. The study suggests that restricting UPF purchases in SNAP could significantly enhance cardiometabolic health and help address dietary inequities, despite modest individual risk reductions.