The Research Brief is a short take about interesting academic work.

The big idea

Low-income parents who live in states that expanded their Medicaid programs under the Affordable Care Act are 4.7% more likely to say they are in good health than their peers in states that have declined to take this step, according to new research I co-authored.

In addition, children of low-income parents living in states that have expanded their Medicaid programs have a 2% lower growth in body mass index, suggesting improvement in their health as well. Preventing excessive weight gain for school-aged children is a priority due to linkages with adult obesity and other health concerns.

These are the main findings from a study I conducted with Caitlin McPherran Lombardi and Lindsey Rose Bullinger.

After combing through nationally representative data, we compared the health of parents and their children in states that had taken advantage of Medicaid expansion under the ACA with those living in states that had not. We also analyzed the changes before and after expansion took effect in the state where these parents lived.

We used statistical analysis to rule out other variables, such as race or ethnicity and marital status, as the source of these differences. We didn’t detect any significant changes in terms of what parents said about their children’s overall health or the use of preventive care.

Why it matters

In 2014, 28 states expanded access to Medicaid, a federal health insurance program primarily for low-income and disabled people under 65 that’s administered independently by every state. States that have expanded the program can enroll people with incomes up to 138% of the federal poverty level – currently US$38,295 for a family of four – as part of the Affordable Care Act. Since then, another 10 states have expanded access. Most recently, Missouri and Oklahoma expanded the program in 2021.

About 2.2 million uninsured adults under 65 who have incomes below the poverty line live in Texas, Florida, North Carolina and the other nine states that have yet to expand access to Medicaid. If they resided elsewhere, they would be able to enroll in the program.

Roughly 60% of the Americans in this situation in 2019 were people of color. Legislation that would further increase access to health insurance has stalled in the Senate.

What other research is being done

Previous studies have shown that Medicaid expansion is leading more low-income parents to get health insurance. Other researchers have also found that concerns about medical costs and health insurance coverage eased psychological distress among low-income parents.

Children from low-income households were already eligible, prior to 2014, for government-provided heath insurance, either through Medicaid or the Children’s Health Insurance Program. Known as CHIP, it’s a joint federal and state program that provides health coverage to kids and pregnant women whose families have low incomes but make too much to qualify for Medicaid.

But multiple studies have found that increased awareness of public health insurance eligibility among parents led to an uptick in children’s insurance coverage as well in what is known as the “welcome-mat effect.”

These studies also echo the findings from prior studies of earlier expansions to Medicaid, which took place in the 1990s and 2000s. That research determined that uninsurance rates for children fell, and that newly insured low-income parents said they had increased their use of preventive medical care and reported significant mental health improvements.

What’s next

We are doing additional research regarding the benefits of Medicaid expansion. One study indicates that low-income children in Medicaid-expansion states made more progress in standardized reading tests compared with kids their age in other states.

We’re also finding that low-income parents in states that expanded Medicaid spent about 13% more time reading with their children, and they were 5% more likely to have consistent dinnertime routines than their counterparts in states that haven’t taken this step.

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Maithreyi Gopalan receives funding from Spencer Foundation and the Population Research Institute that is funded by an infrastructure grant by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.