Effect of Medicaid Coverage on ED Use — Further Evidence from Oregon’s Experiment

The effect of Medicaid coverage on health and the use of health care services is of first-order policy importance, particularly as policymakers consider expansions of public health insurance. Estimating the effects of expanding Medicaid is challenging, however, because Medicaid enrollees and the uninsured differ in many ways that may also affect outcomes of interest. Oregon’s 2008 expansion of Medicaid through random-lottery selection of potential enrollees from a waiting list offers the opportunity to assess Medicaid’s effects with a randomized evaluation that is not contaminated by such confounding factors. In a previous examination of the Oregon Health Insurance Experiment, we found that Medicaid coverage increased health care use across a range of settings, improved financial security, and reduced rates of depression among enrollees, but it produced no detectable changes in several measures of physical health, employment rates, or earnings.