We study the effect of damage caps adopted in the 1990s and 2000s on medical malpractice claim rates and payouts. Prior studies found some evidence that caps reduce payout per claim, but mixed and weak evidence on whether caps reduce paid claim rates and payout per physician. However, most prior studies do not allow for the gradual phase-in of damage caps, which usually apply only to lawsuits filed after the reform's effective date, or only to injuries after the effective date. Once we allow for phase-in,...