States have begun to remove people from Medicaid, something they could not do for three years during the COVID-19 pandemic.

State Medicaid programs are reviewing the eligibility of roughly 90 million beneficiaries in the U.S., now that a rule suspending that process has expired. Those who remain eligible should be able to keep their coverage, and those who don't will lose it.

But new data from states that have begun this process show that hundreds of thousands of people are losing coverage – not because of their income, but because of administrative problems, like missing a renewal notification in the mail.

And a poll this week from KFF found that 65% of Medicaid enrollees across the country didn't know states can now remove people from the program if they are not eligible or don't complete the renewal process.

"I've been worried about this for a year and a half," says Joan Alker, a public policy researcher and the executive director of the Georgetown Center for Children and Families. "If anything, I'm concerned that it's going worse than I expected in some places."

For instance in Florida, nearly 250,000 people lost coverage in April, and for 82% of them, it was for procedural reasons, Alker found after reviewing data provided by the state to federal health officials. Many of those who lost coverage are children, because Florida didn't expand Medicaid to more low-income adults.

Liz Adams of Plant City, Fla., has two kids and they were among those in Florida who lost coverage in April. She found out while trying to figure out the time of her son's biopsy appointment. Her son survived leukemia and has a variety of ongoing health problems.

"I called the surgery center [asking] what time is this appointment? 'Oh, we canceled that. He doesn't have insurance," she says. "So I jump on the portal and sure enough, they don't have insurance."

She was incredibly frustrated that she then had to try and re-enroll her children in health insurance, while figuring out how to get her son's care back on track.

"I waited a year to get in with a rheumatologist, and we finally got the biopsy and we finally got blood work ordered, and I can't go do any of it because they canceled my insurance," she says.

With the help of the Family Healthcare Foundation, she was able to sign up her kids for new health coverage, and she eventually got her son's biopsy rescheduled for the end of June.

"I am very worried about Florida," Alker says. "We've heard the call center's overwhelmed, the notices are very confusing in Florida – they're very hard to understand."

Some other states have also dropped many people from Medicaid. But Alker says that unwinding is not going badly in every state.

"We're really seeing divergence here," she says. "We've seen very, very concerning numbers from Florida, from Arkansas, from Indiana, but we've seen much more reassuring numbers from Arizona and Pennsylvania."

In Pennsylvania, for instance, only 10% of people whose Medicaid eligibility was reviewed in April lost coverage, and in Arizona, that figure was 17%, according to a state report.

The federal government can require states to pause disenrolling people from Medicaid when there are problems, Alker says, but it remains to be seen if federal health officials will use that enforcement power.