New research finds that expanding low-income adults’ access to Medicaid substantially increases health care use, reduces financial strain on covered individuals, and improves their self-reported health and well-being. The MacArthur-supported study by researchers from Harvard School of Public Health, Massachusetts Institute of Technology, the National Bureau of Economic Research, and Providence Health & Services is the first to evaluate the impact of insuring the uninsured in the U.S. using a randomized controlled trial, the highest standard for scientific studies.