While the Affordable Care Act’s Medicaid expansion was designed to help the large number of uninsured adults who could not afford private insurance, the policy change has proven to be immensely helpful to children too. In February 2021, we released a report on the critical link between Medicaid expansion for adults and improvements to child health coverage. We found that between 2016 and 2019 states expanding Medicaid saw their child uninsured rates jump from 3.5 percent to 4.1 percent while states that had refused the expansion saw uninsured rates jump from 6.5 percent to 8.1 percent. We also reviewed research linking improved child health coverage in expansion states to parents gaining their own coverage, protecting families from medical debt and improving measures of child health.
Further research over the last two years has only added to the evidence that Medicaid expansion for adults also helps children. A study in 2021 by researchers at Columbia University Mailman School of Public Health, the University of Chicago, and MIT looked back at Oregon’s 2008 Medicaid expansion. This study is particularly powerful because of a unique element of Oregon’s 2008 expansion – adults were randomly assigned to expansion and non-expansion groups. Looking at these groups of parents, the researchers found that for every nine adults who got health coverage, one more child also got health coverage as compared to the non-expansion group. This “welcome mat” effect occurs when previously Medicaid-eligible people, children in this case, are enrolled in Medicaid due to expansion of new Medicaid coverage to parents and other adults.
In 2022, researchers looking specifically at health care delivery effects of Medicaid expansion found that children had more insured visits in Community Health Centers when their parents gained Medicaid coverage: “Children with a parent who gained Medicaid had 4.4% more insured visits post- compared to pre-ACA.” Children were simply more likely to see the doctor in expansion states. And an article just published in the Lancet journal of Child and Adolescent Health summarized research findings showing that, “[E]xpansion states improved perinatal and maternal health, increased preventive care use, decreased incidence in child neglect, decreased high school dropout rate, and had a nearly 50% greater reduction in infant mortality.”
In 2022 researchers writing in the Journal of Clinical Oncology found that survival rates of young adults with cancer was associated with Medicaid expansion status of the state in which they live – young adults survived longer in Medicaid expansion states. Following up on this research in 2023, researchers at Washington University and Duke University found that Medicaid expansion was associated with improved overall survival and outcomes for children with cancer – showing the effects of broader coverage. In addition, the Urban Institute estimated in a 2023 paper that should the remaining non-expansion states all expand Medicaid the overall number of uninsured children in these states would drop by 7.3% because of the “welcome mat” effect when parents obtain coverage themselves through Medicaid expansion.
Finally, the US Census Bureau released its own comparison of Medicaid expansion state decisions and health insurance coverage for children based on 2021 Current Population Survey data. While the nationwide report found overall rates of uninsured children had dropped, the report also found that the percentage of children without health insurance was again much higher in non-expansion states (7.1%) compared to a lower uninsured rate in states that have expanded Medicaid (4.0%).
As federal and state policy changes affect health coverage rates for children, one thing is consistent in the data over many years. Expanding Medicaid coverage for parents is also beneficial for children even if they are not directly qualified for the new expansion coverage offered their parents and other adults. In expansion states, children continue to gain health coverage at higher rates, see health providers more for needed visits, and experience better health outcomes.
