The uninsured rate among children increased between 2016 and 2017, representing 276,000 more uninsured children across the U.S. and the first observed increase in uninsured children since 2008, according to a recent report by the Georgetown University Center for Children and Families.

Coverage gains among parents appear to have stalled, according to an analysis from Urban Institute, a Washington, D.C.-based think tank.

The analyses, used newly released data from the Census Bureau’s 2017 American Community Survey.

Researchers found that the uninsured rate among children increased from 4.7 percent in 2016 to 5 percent in 2017.

During the same period, the uninsured rate among parents remained relatively stable, at 11.5 percent in 2016 and 11.6 percent in 2017.

Researchers said rising uninsured rates among adults and children appears concentrated in states that didn’t expand Medicaid for adults under the ACA.

The uninsured rate among children slightly increased in expansion states between 2016 and 2017 (3.5 percent vs. 3.7 percent), but the uninsured rate among children was higher in nonexpansion states, climbing year over year from 6.4 percent to 7 percent, Georgetown Center for Children and Families researchers found.

Similarly, the Urban Institute analysis found that the uninsured rate remained relatively the same among parents in expansion states (8.5 percent in 2016 vs. 8.4 percent in 2017) but significantly climbed in nonexpansion states on average (16.3 percent in 2016 vs. 16.6 percent in 2017).

“The coverage gaps for children and parents between expansion and nonexpansion states suggest that adoption of the expansion by additional states — as is being implemented January 1, 2019, in Virginia; as ordered by the courts in Maine; and as voters in Idaho, Nebraska, and Utah approved in ballot initiatives in the 2018 midterm election — could serve to improve overall coverage rates,” researchers concluded.

But “a number of additional policy changes are on the horizon that could further erode coverage,” such as Medicaid work requirements and the elimination of the ACA’s individual mandate penalties, effective Jan. 1, the analysts said.