AUGUSTA — Thousands of Mainers are waiting to find out if they’re eligible for Medicaid coverage, potentially putting off needed medical care while state and federal officials sort out the bureaucratic backlog.

Nationally, more than 6 million low-income Americans have gained Medicaid coverage through an expansion of the health insurance program under the Affordable Care Act. But even Maine and other states that opted against expanding Medicaid are seeing rising enrollment, through what health policy experts call the “woodwork effect.” Individuals who previously were eligible under existing Medicaid criteria but unenrolled are seeking coverage amid publicity about new, more affordable health insurance options and the requirement that most Americans get health coverage or pay a penalty.

Many applied through Healthcare.gov, the federal insurance marketplace set up under the health reform law. Applicants were encouraged to log on to the site to see if they were eligible for Medicaid, based on their income and other factors, with the state making the final determination.

Maine received basic eligibility information through Healthcare.gov on about 10,000 applications, according to the state Department of Health and Human Services. Applications can reflect more than one person seeking coverage. The state determined most applications didn’t qualify for Medicaid, leaving about 3,900 potentially eligible. Of those, 1,664 were determined eligible, and the state is still processing the remainder, according to DHHS spokesman John Martins.

Maine residents seeking Medicaid, or MaineCare, coverage also can apply directly with the state. Many were encouraged to after technical problems plagued the launch of Healthcare.gov. About 5,300 applications filed through the state also are pending, according to figures DHHS recently provided to the state’s health exchange advisory committee.

The early glitches that prevented applicants’ data from reaching states have been resolved, according to federal officials. The U.S. Centers for Medicare and Medicaid Services say Maine is one of just three states — along with Republican-led Alaska and Kansas — that can’t accept data on applicants transferred through Healthcare.gov, according to a Washington Post/Kaiser Health News report.

Maine Department of Health and Human Services Commissioner Mary Mayhew disputed that characterization, calling it a “complete distortion,” and claiming the federal government pressured states to provide Medicaid coverage despite missing information on applicants.

For months, states received only limited information on individuals seeking Medicaid coverage that lacked sufficient detail to accurately determine eligibility, she said in a Tuesday statement.

“To make matters worse, for political expediency, the federal government wanted states to ignore income verification and other missing information and simply make individuals eligible because of their inability to provide complete information,” Mayhew said. “Maine was one of three states that were not willing to sacrifice program integrity and grant eligibility to tens of thousands of applicants without all of the information needed to accurately make a determination.”

In December, the U.S. Centers for Medicare and Medicaid Services pledged to improve the quality of applicant information sent to states. The agency gave states the option of using the limited information to temporarily enroll applicants who likely were eligible and promised federal matching funds to pay for that coverage.

As of April, the federal government has provided complete information for Medicaid applicants, but Maine DHHS can’t process it, according to Jack Comart, litigation director for Maine Equal Justice Partners, a nonprofit organization that assists low-income residents.

“It’s not the federal government’s fault anymore,” he said. “It’s Maine’s problem now.”

Mayhew’s statement highlighted the technical problems of previous months but didn’t address whether the state is receiving complete information on MaineCare applicants from the federal government.

Maine DHHS didn’t respond to a request for clarification.

Meanwhile, thousands of Mainers are waiting for health care coverage before seeking treatment for their medical conditions, according to Sara Gagne-Holmes, executive director of Maine Equal Justice Partners.

“There’s definitely a fear of not being able to afford access to care, and therefore putting off much-needed care until their situation becomes acute,” she said. “So the longer we delay resolving who is to blame … the more we are putting people at risk.”

Maine has gone “above and beyond” to accommodate Mainers who applied for MaineCare through Healthcare.gov, Mayhew said in the statement. DHHS has sent more than 10,000 letters and made thousands of phone calls to follow up with applicants and obtain income and other eligibility information, she said.

“More than half of those who we contacted were not eligible for Medicaid, further illustrating the importance of Maine’s fiscally sound decision to not waive eligibility requirements,” Mayhew said.

As for how long applicants through Healthcare.gov have been waiting, Maine DHHS does not have “any readily available data,” the department said. MaineCare coverage can be extended retroactively for three months, but some applicants may have been waiting since October 2013, when open enrollment began, Comart said. It remains unclear when the clock starts ticking on those applications, he said.

So far in 2014, the average time to process MaineCare applications filed directly with the state is 21.57 days, according to DHHS figures. That’s up from 17.22 days in 2013.

Before the technical problems, Healthcare.gov was envisioned as providing a “one-stop shopping” experience for Medicaid applicants. Consumers were expected to plug their income and other information into online forms that the federal government forwarded to states, which would complete the eligibility process without extended follow-up.

Nationally, more than 1.7 Americans are waiting for their Medicaid applications to be processed, some for up to eight months, according to the Washington Post/Kaiser Health News report.

Some states with backlogs expanded Medicaid under the Affordable Care Act, leading to large influxes of new applicants. Others that opted against expanding the program also are recording long waits, according to the report. Federal regulations require states to process applications within 45 days.

Maine was not among the 26 states that expanded Medicaid under the health reform law to those earning less than 138 percent of the federal poverty level, or about $32,900 for a family of four.