The U.S. Centers for Medicare and Medicaid Services said it was establishing a special enrollment period through Nov. 2 for those people to sign up under the federal exchange created under the health overhaul law.
The Wisconsin Department of Health Services estimates that about 25,800 out of 63,000 adults who lost that coverage had yet to sign up for subsidized insurance plans under the federal law.
They lost coverage after Gov. Scott Walker and the Republican-controlled Legislature tightened income eligibility for the state's Medicaid coverage from 200 percent of poverty to 100 percent. That made the income cutoff for coverage $11,670 for an individual and $23,850 for a family of four.
The people losing coverage originally had until June 30 to sign up for plans sold through the exchange, two months longer than the open enrollment period for most other people.
Democratic U.S. Sen. Tammy Baldwin asked the federal government for the special enrollment period last week.
The decision to offer the expanded enrollment period brought praise from health care advocates who had been calling for it, along with a renewed call for Walker to accept federal money to expand Medicaid coverage to those earning up to 138 percent of the poverty level.
Walker rejected the money in taking his approach that combined tightening income eligibility while also eliminating a waiting list for childless adults. Walker's administration previously reported Wednesday that 97,509 additional people had obtained Medicaid coverage through June 30.
Walker's spokeswoman referred requests for comment to his Department of Health Services. Its spokeswoman, Claire Smith, issued a statement saying the department would send a letter to the affected people letting them know about the special enrollment period.
"It is up to individuals whether or not they choose to purchase health care plans through the federal exchange," she said. "For a variety of reasons, including the well-publicized issues with the exchange and the price of coverage, people may have chosen not to purchase through the exchange."