Federal figures show Georgia’s Medicaid and PeachCare enrollment jumped 16 percent since October – the highest percentage increase among states that have rejected the expansion of Medicaid under the Affordable Care Act.

The Georgia jump greatly exceeds that of the second-highest increase among non-expansion states: 9.5 percent in Montana.

Expanding Medicaid involves extending enrollment in the government program to many low-income people who had not previously been eligible.

As a group, the states not pursuing expansion saw enrollment in Medicaid and their Children’s Health Insurance Program rise by 4 percent. (The children’s program is called PeachCare in Georgia.) States embracing Medicaid expansion saw an average increase in enrollment of 18.5 percent since October, when open enrollment on the health insurance exchanges began.

The enrollment data from the Department of Health and Human Services, released Friday, are part of various studies underscoring the insurance changes created through the ACA.

Yet Georgia Medicaid officials Monday released figures that showed a much smaller percentage hike in Medicaid and PeachCare enrollment since October – 5.6 percent, rising by more than 100,000 to almost 1.9 million members.

A spokeswoman for the Georgia Department of Community Health said Monday that state officials had not yet had the opportunity to study the federal report fully.

There have been past discrepancies on Medicaid enrollment between what the federal figures show and what state officials have reported. (Here’s a recent GHN article on this gap.)

Tim Sweeney, health policy director for the Georgia Budget and Policy Institute, said Monday that the difference in those figures makes him cautious about drawing conclusions from the HHS data.

Still, he said, Georgia was known prior to the ACA to have a large number of people who were already eligible for Medicaid and PeachCare but had not enrolled. They could sign up whether the state opted for expansion or not.

The ACA was expected to lead tens of thousands of these Georgians – mostly children – to join Medicaid and PeachCare because of the “woodwork effect” (people coming out of the woodwork).

Last week, a nationwide survey conducted by Gallup showed the percentage of Georgians who don’t have health insurance declined slightly this year, from 21.4 percent last year to 20.2 percent this year.

Other states showed more improvement in their uninsured rates. That resulted in Georgia moving from being the state with the seventh-highest percentage of uninsured in 2013 to the state with the third-highest rate of uninsured this year, Tom Crawford of the Georgia Report recently pointed out.

The only states that have a higher percentage of uninsured people in 2014, according to the Gallup data, are Texas, at 24 percent and Mississippi, at 20.6 percent.

Gallup said states that established a state-operated health insurance exchange and agreed to expand Medicaid coverage have experienced the largest decreases in the percentage of citizens who lack health insurance.

Two Southern states that took both steps were Arkansas, where the uninsured rate declined from 22.5 percent in 2013 to just 12.4 percent this year, and Kentucky, where the percentage of residents without health insurance dropped from 20.4 percent to 11.9 percent, Crawford noted.

Sweeney of GPBI said the Gallup figures and other data show Georgia “is one of the states that is in most need of Medicaid expansion.’’

The state has the fourth-highest number of uninsured children, he added. “We have a lot of people who are eligible but not enrolled, especially kids.’’

Another recent report, done by the Urban Institute, said that Georgia’s decision not to expand Medicaid will cost the state’s hospitals $12.8 billion in lost reimbursements over a 10-year period.

The Urban Institute study, released this month, tracked the effect on hospitals in other states not expanding the government program. The states with the greatest financial impact on hospitals over 10 years are Texas, at $34.3 billion, and Florida, at $22.6 billion.

Andy Miller is the founder of Georgia Health News.