Both children and parents experienced steep declines in uninsurance following implementation of the major coverage provisions of the Affordable Care Act (ACA) in 2014. Between 2013 and 2016, uninsurance fell by nearly 40 percent for both groups. But these coverage gains stalled starting in 2017 and 2018. In this brief, we use data from the American Community Survey to assess trends in coverage for children and parents through 2019. Our main findings are as follows:

• Altogether, the number of uninsured children and parents rose by just over 1.0 million between 2016 and 2019. Nearly 700,000 more children and more than 300,000 additional parents were uninsured in 2019 than in 2016.
• An estimated 4.0 million children (5.2 percent) were uninsured in 2019.
• Children’s uninsurance rose between 2016 and 2019 both in states that had implemented the ACA’s Medicaid expansion and those that had not (hereafter called Medicaid expansion and nonexpansion states). However, the increase was larger in nonexpansion states on average. In 2019, as in prior years, uninsurance remained higher in nonexpansion states: 7.6 percent of children in nonexpansion states were uninsured, compared with 3.8 percent of children in expansion states.
• Children’s uninsurance also continued to vary widely across states. Texas remained the state with the highest rate of uninsured children (11.9 percent) and was among the states with the largest increases in uninsurance between 2016 and 2019.
• Underlying the rise in uninsurance among children was a decline in take-up of Medicaid/Children’s Health Insurance Program (CHIP) coverage. An estimated 91.9 percent of Medicaid/CHIP-eligible children without other coverage participated in the programs in 2019, compared with 93.4 percent in 2016. Participation fell in both expansion and nonexpansion states, but the drop was larger in nonexpansion states.
• An estimated 2.3 million children, constituting 57.7 percent of all uninsured children, were eligible for Medicaid/CHIP but uninsured in 2019.
• Uninsurance among parents rose from 11.2 percent in 2018 to 11.7 percent in 2019.
• Parents’ uninsurance rose in both expansion and nonexpansion states in 2019, and parents were twice as likely to be uninsured if they lived in a nonexpansion state (17.2 percent) than if they lived in an expansion state (8.6 percent).
• In Medicaid expansion states in 2019, the Medicaid participation rate among parents not enrolled in other coverage averaged 84.0 percent, nearly 10 percentage points lower than the Medicaid/CHIP participation rate among children in those states (93.7 percent).
• We estimate that more than 1 million parents were likely eligible for Medicaid but uninsured in 2019, and 70.0 percent of these parents had at least one child who was enrolled in Medicaid/CHIP.