[Editor’s Note: You can find state level Medicaid/CHIP participation rates on CCF’s State Data Hub.]

Since the American Community Survey (ACS) was first released in 2008, the Urban Institute has estimated the share of uninsured children who are eligible but not enrolled in Medicaid and CHIP. Several weeks ago, Urban released its latest analysis based on the most recent ACS data from 2019. Urban’s methodology examines the demographic characteristics of uninsured children to estimate the share that are likely eligible and approximate participation rates in Medicaid and CHIP. Participation rates have an inverse correlation with uninsured rates. As the participation rate goes up, the uninsured rate declines. This was the case between 2008 and 2016 based on Urban’s annual updates. But just as the uninsured rate began to climb in 2017 for the first time in a decade, the participation rate began to decline.

National average participation rates for children reached a high of 93.4 percent in 2016, up from 88.7 percent in 2013. But between 2016 and 2019, the participation rate – like the uninsured rate, reversed course – declining to 91.9 percent. The 0.9 percentage-point drop in participation between 2018 and 2019 was the largest annual drop in Medicaid/CHIP child participation that Urban has observed since the ACS began collecting coverage data in 2008. Participation rates for children vary significantly by state, from a low of 79 percent in Wyoming to a high of 97.7 percent in Massachusetts.

The peak participation rate in 2016 is a strong indication of the positive impact of the Affordable Care Act (ACA) on children’s coverage starting in 2014. You can see that evidence in the difference in participation in expansion vs. non-expansion states in the report’s Figure 6 (below). In 2019, the participation rate in non-expansion states was 89 percent – almost 5 percentage points lower (4.7) than expansion states.

Urban estimates that 57.7 percent of, or 2.3 million, uninsured children, were eligible but not enrolled in 2019, up from 2 million in 2016. An alternative analysis that includes families with reported income just over Medicaid or CHIP eligibility threshold indicates that as many as two-thirds (65.4 percent) of uninsured children may be eligible for Medicaid or CHIP. The alternative analysis may help account for differences in how income is reported versus how it is calculated for eligibility purposes. Texas, California, Florida, and Georgia each have more than 100,000 eligible but uninsured children, with Texas topping the list with nearly half a million (460,000) uninsured children accounting for 1 out of every 5 of the nation’s children who are likely eligible but not enrolled.

Overall, participation was lower among parents (84.0 percent) than children (93.7 percent) in the 34 states that had expanded Medicaid at the time the data was collected. Nearly 1.2 million parents were eligible but not enrolled, most of whom had a child enrolled in Medicaid.

Unfortunately, we won’t be able to assess the impact of Medicaid’s COVID-related continuous enrollment requirement on participation in 2020 since the American Community Survey data will not be published due to data collection issues during the early months of the pandemic. Still, we know that more than half of all uninsured children are eligible for Medicaid and CHIP, and Medicaid expansion, as well as other improvements like covering lawfully residing immigrant children and streamlining enrollment processes, can go a long way to ensure that all children have continuous access to the health care they need to thrive.