In this study, Marguerite Burns et al. used insurance claims and Medicaid enrollment files to measure the change in health care use by rural, low-income childless adults after enrollment into a new public insurance program. The investigators found that public insurance enrollment led to substantial increases in outpatient visits, including preventive visits, but not mental health visits. It also led to increases in inpatient stays but it was inconclusive whether it led to increased ED visits.