This paper uses data from the 2000-01 and 2003 Community Tracking Study household surveys to examine how decreases in enrollment in Medicaid and the State Children's Health Insurance Program (SCHIP) and increases in the number of uninsured people would affect the volume and distribution of emergency department (ED) use among low-income people. A decrease in Medicaid/SCHIP enrollment would lead to an increase in ED visits by the uninsured but little change in overall ED volume. The results suggest that cost containment efforts that reduce eligibility and enrollment will achieve cost savings largely by reducing access and shifting costs away from Medicaid/SCHIP.