Medicaid Expansion and Medical Liability Costs

This paper examines the impact of health insurance expansion on medical liability costs using the case of the Affordable Care Act’s (ACA) Medicaid expansion. Medicaid expansion has increased the demand for medical services, but in doing so it may also have increased physicians’ liability in medical practices. By studying medical malpractice insurers’ performance in the U.S. for the period 2010–2018, we find insurers operating in states with Medicaid expansion experienced significantly higher medical liability costs than those in non-expansion states. While insurers in expansion states did increase premiums, the increase was not enough to fully offset rising costs. In addition, we do not find evidence that tort reforms mitigate ACA-induced malpractice liability costs. By exploring the frequency and severity of malpractice claims, we find Medicaid expansion increased malpractice costs mainly by increasing the claim frequency, while tort reforms generally focus on reducing claim severity.