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...

Health insurance confers benefits to the previously uninsured, including improvements in health, reductions in out-of-pocket spending, and reduced medical debt. But because the nominally uninsured pay only a small share of their medical expenses, health insurance also provides substantial...