Updated

The Obama administration announced Friday that enrollment records for one in four Americans who selected health plans on HealthCare.gov in October and November could contain errors, raising concerns that consumers who think they have coverage won't actually be enrolled on Jan. 1.

Centers for Medicare and Medicaid Services spokeswoman Julie Bataille said recent fixes to HealthCare.gov have brought the error rate on forms sent to insurance companies down to about one in 10 for files generated after Dec. 1, The Wall Street Journal reported.

The electronic files, known as 834 forms, give insurance companies basic information about would-be customers, including their name, address, contact information and Social Security number. Insurance companies have reported issues with the files since the law's rollout.

"The new process put in place this week is making a difference. The enrollment files are getting better, but there is more work to do to ensure consumers are covered," Karen Ignani, the chief executive officer of insurance industry trade group, America’s Health Insurance Plans, said in a statement obtained by the New York Post on Friday.

CMS is reaching out to hundreds of thousands of consumers who have tried to enroll for health coverage but aren't enrolled, according to Bataille, who said consumers should be contacted by the insurance company for a payment after selecting a plan.

"Our clear priority is fixing any remaining bugs causing problems and working to make sure every 834 form past and present is resolved," Bataille said, according to The Journal.

Ms. Bataille said errors with the enrollment forms include duplicate files, lack of a file altogether, or a file with mistaken data such as a child incorrectly being listed as a spouse.

AHIP spokesman Robert Zirkelbach told FoxNews.com last week that insurance companies have received duplicative and inaccurate forms, and "in some cases, plans are not getting the enrollment files at all." Getting that fixed, he said, is "critical."

Though the administration has given people until the end of March to sign up for coverage if they want to avoid a fine, coverage for many is supposed to start on Jan. 1. That leaves less than 30 days to fix the remaining glitches.

The administration announced last week it is working on a system to pay insurers its portion of premiums and cost-sharing payments. A temporary workaround has been proposed that would allow insurers to estimate how much they are owed, and submit the bill to the government.

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