New Research Shows Medicaid Expansion Reduced Mortality in Low-Income Adults

A new working paper – entitled “Saved by Medicaid: New Evidence on Health Insurance and Mortality from the Universe of Low-Income Adults” – provides the strongest evidence to date that expanding access to health insurance can save lives.

Coauthored by Bruce D. Meyer, the McCormick Foundation Professor at the University of Chicago Harris School of Public Policy, and Angela Wyse, PhD’24, now an assistant professor of economics at Dartmouth College, the paper finds that Medicaid expansions under the 2010 Affordable Care and Patient Protection Act (ACA), sometimes known as “Obamacare,” and earlier state waivers reduced mortality among low-income adults by 2.5 percent, representing a 21 percent decrease in the mortality hazard for new enrollees, saving about 27,400 lives between 2010 and 2022. An additional 12,800 deaths could have been prevented had all states opted to expand Medicaid.

While the idea that health insurance can improve health may seem intuitive, economists have long debated whether and to what extent such coverage saves lives. With this new research, Meyer and Wyse analyze a dataset of 37 million low-income adults, identified by linking 2010 Census records with administrative tax data, making the study more than 60 times the size of the next-largest study on the topic.

Their findings show that Medicaid expansions led to a 12 percent increase in enrollment and significantly reduced mortality—not just among older adults, but also younger ones, who accounted for nearly half of the life-years saved.

“With younger adults comprising a large share of the low-income population and having more years ahead, their survival gains have especially high policy relevance, and have not been studied in this way before,” Meyer said. “As policymakers look to make changes to Medicaid in the upcoming budget bill, they should not overlook the impact on younger adults.”

The study also addresses cost-effectiveness. The paper finds that each life saved through expansion cost approximately $5.4 million, or $179,000 per life-year saved, well below standard benchmarks used to assess the value of life and health interventions in economics.

“For policymakers grappling with questions about the costs and benefits of expanding public health insurance,” Wyse noted, “the findings of our work suggest that not only did the ACA have significant impacts on health outcomes – saving tens of thousands of lives – it did so in what appears to be a relatively cost-effective way.”