A new study today, the most robust of its kind in 40 years, concludes that Medicaid makes a big difference for its enrollees. The study, authored by the National Bureau of Economic Research, documented that Medicaid recipients, on average, were more likely to have a usual doctor, obtain preventative services, and overall, were healthier and felt better.

For advocates, this is no surprise.

The study, based on patients in Oregon, is unique. Because of limited funds in Oregon, the state allocated Medicaid slots through a lottery, enrolling 10,000 of its 90,000 applicants. This allowed researchers to ethically measure the effect of people who enrolled in Medicaid against those who did not. This randomized trial is the gold standard for research studies.

There were also other benefits to having Medicaid. The study found that people with Medicaid were less likely, on average, to have medical debt. Medicaid offers Americans both financial and health security.

The study results are a firm rebuttal to Medicaid critics who claim that vulnerable patients would fare better by relying on charity care and emergency rooms than insurance. As the lead author MIT economist Amy Finkelstein notes: “The bottom line is that Medicaid really matters in people’s lives…There is a large concern out there about whether Medicaid actually makes a difference, and now we actually have evidence.”

— Eva Marie Stahl, Policy Analyst