Even without expanding Medicaid, both Tennessee and Georgia have seen an uptick of people enrolling in these safety-net health care programs - meaning both states are facing rising Medicaid costs.
The increase shows the impact of a phenomenon health experts call the "woodwork effect."
These are not people newly eligible for Medicaid. Instead, they are thousands who were already eligible - but had not enrolled for one reason or another.
But with the highly publicized rollout of the Affordable Care Act insurance marketplaces and the national push to apply for coverage, people in that "eligible-but-not-enrolled" category have entered Medicaid in unexpectedly high numbers.
Initial reports show that Georgia had 98,800 new Medicaid enrollees during the six months people were applying for coverage through Healthcare.gov - a 5.8 increase according to the analysis Avaleye Health.
Tennessee saw 53,700 enrollees, a 4.3 percent increase,
The figure, which does not include enrollment in Children's Health Insurance Program, outpaced TennCare's original expectations for 47,000 new enrollees by June 30, the end of its fiscal year.
"The number has surpassed what we estimated for the budget year," said TennCare spokeswoman Sarah Tanksley.
According to Tennessee's matching guidelines, the state is on the hook for 30 percent of its Medicaid expenses, while the federal government covers 70 percent.
But according to TennCare's 2015 budget presentation, the state does not plan to increase its spending from the $3.3 billion it allocated this past year. TennCare officials did not respond by Tuesday evening to requests for more details about how the increase in enrollees would be handled.
Health care advocacy groups in Tennessee say the newly insured are people who long had the door to Medicaid open to them - they had just never gone through it.
But efforts to reach those eligible people, they say, were led by volunteers and outreach organizations, with little assistance or resources from the state.
On the contrary, they say, new state policies - namely, the removal of all traditional in-person TennCare assistance typically provided in Department of Human Services offices - created obstacles in the enrollment process.
"We know from years of experience if you want to reach those eligible-but-unenrolled folks, you have to remove the red tape. That has not been the case in Tennessee," said Michele Johnson, executive director of the Tennessee Justice Center, who added that the enrollment increase could be credited to "an incredible volunteer spirit, where people devoted thousands of hours" connecting people to coverage during the six-month enrollment push.
The Tennessee Justice Center and other advocacy groups in the state have decried what they call an "eligibility purgatory" created when Tennessee handed over all eligibility screening to the federal government after the state's own new $35.7 million computer system was not ready to handle the process.
And out of the 53,700 newly-enrolled Tennesseans, it still is unclear whether these people's applications have actually been processed and whether they are currently receiving services, says Walter Davis, executive director of the Tennessee Health Care Campaign.
"What we don't know is how many of these people are actually receiving benefits at this time. Are they through the system? It hasn't been a transparent process," he said.
State officials have said that the new process is the most convenient and accessible method for signups, and that the state's new computer system should be finished this year.
Meanwhile, both groups continue to push for Medicaid expansion, which would open up TennCare coverage to an estimated 140,000 more Tennesseans.
Under expansion, the federal government pays the entire cost for that group through 2016, then phasing down to a 90 percent share.
About half of states have accepted the offer to expand coverage in this way. But even without that, both Davis and Johnson say the sign-up process could be much easier for those seeking coverage if Tennessee officials give more support to enrollment efforts.
"We want to see the TennCare process work for the people who should be eligible," Davis said.
Because open enrollment for Medicaid is year-round, more "woodwork" enrollment may continue throughout 2014. Additionally, many states are still processing their eligibility files, which could result in higher overall totals.
Contact staff writer Kate Harrison at firstname.lastname@example.org or 423-757-6673.