The number of uninsured Georgia children fell by more than 50,000 in 2014, the first year of full implementation of the Affordable Care Act, a new report found.

That drop of 53,000 was the fourth-biggest decline in the United States. Yet it left Georgia still having 210,000 kids without coverage, the fourth-largest total in the nation, according to the Robert Wood Johnson Foundation report, released Thursday.

The rate of uninsured children in Georgia fell from 10 percent to 8 percent in 2014, still among the highest percentages among the states.

Nationally, the report said that the number of children lacking health insurance fell by 1 million in 2014, which lowered the uninsured children’s rate from 7.5 percent to 6.3 percent.

The ACA was clearly the biggest force behind the decrease in uninsured children in Georgia, said Bill Custer, a health insurance expert at Georgia State University. Many parents found out that their kids were eligible for Medicaid or PeachCare for Kids during the enrollment process for the ACA insurance exchange, he said.

“The ACA helped to streamline the enrollment process,’’ Custer added.

The findings were similar to a report in October from Georgetown University Health Policy Institute’s Center for Children and Families, which put the number of uninsured Georgia children at 189,000.

But the new report, conducted by researchers at the University of Minnesota, counted children through age 18, while the Georgetown study did not include 18-year-olds, said Elizabeth Lukanen of Minnesota’s State Health Access Data Assistance Center.

The percentage of Georgia children on Medicaid or PeachCare rose by 2 percentage points during 2014, while those with private coverage remained about the same, the report said.

The decline in Georgia’s uninsured children came across the board, including “all incomes, races and ethnic groups,” Lukanen said.

The remaining uninsured tend to be kids in the lowest-income families, she said. They include immigrant children, who, if not in the country legally, are not eligible for the public coverage.

Custer said that in Georgia, “we have a large population under 200 percent of [the federal poverty level], and children are a big part of it.”

Many of these children may have parents who remain uninsured, and have not engaged in the enrollment process because they are in the “coverage gap’’ – making too much income to qualify for Medicaid but not enough to get discounts on coverage through the exchange.

Thirty states have filled that gap through Medicaid expansion under the ACA, which extends the program’s coverage to more people. Georgia has decided against expansion, citing the costs to the state.

“Parents who gain coverage leads to more kids gaining coverage,” Lukanen said.

The report shows that nearly half the nation’s 5 million uninsured children live in just six states — California, Texas, Florida, New York, Georgia and Arizona. And while it’s true that these six also have high overall populations, as a group they contain far less than half of the nation’s people.

Polly McKinney of the advocacy group Voices for Georgia’s Children noted that while the number of Georgia kids without insurance is dropping, “the number is still high and illustrates the significant need to improve not only our enrollment systems, but to increase the public awareness about the importance of making sure all children have health insurance, whether public or private.”

“On top of that, we know that when children are insured, there is one less barrier to good, timely and cost-effective care, which is key to keeping kids in school and on the path to long-term success,” she added.