Lack of health insurance and a regular source of care (RSOC) are associated with suboptimal health care. This study examined the impact of a statewide program called the Community Healthcare Access Program (CHAP), which provided a RSOC for uninsured persons in Delaware. This cohort study used survey data to compare health care utilization from baseline to six months after enrollment in CHAP. The 795 eligible enrollees had significant increases in Pap tests, mammograms, breast exams, cholesterol tests, sigmoid/colonoscopy and influenza immunizations but not stool blood tests or pneumococcal immunizations. There was a significant decrease in the proportion with emergency department visits but not hospitalizations, and there was a significant improvement in satisfaction with care. Delaware's CHAP program is associated with significant improvements across many measures of health care utilization and represents a successful and financially feasible method for states to improve health care for their uninsured populations.