We use comprehensive patient-level discharge data to study the effect of Medicaid on the use of hospital services. Our analysis relies on cross-state variation in the Affordable Care Act's Medicaid expansion, along with within-state variation across ZIP Codes in exposure to the expansion. We...

The Patient Protection and Affordable Care Act (ACA) is the most comprehensive reform of the U.S. medical system in at least 45 years. The ACA transforms the non-group insurance market in the United States, mandates that most residents have health insurance, significantly expands public...