The enrollment records for a significant portion of the Americans who have chosen health plans through the online federal insurance marketplace contain errors — generated by the computer system — that mean they might not get the coverage they’re expecting next month.
The errors cumulatively have affected roughly one-third of the people who have signed up for health plans since Oct. 1, according to two government and health-care industry officials. The White House disputed the figure but declined to provide its own.
The mistakes include failure to notify insurers about new customers, duplicate enrollments or cancellation notices for the same person, incorrect information about family members, and mistakes involving federal subsidies. The errors have been accumulating since HealthCare.gov opened two months ago, even as the Obama administration has been working to make it easier for consumers to sign up for coverage, the government and industry officials said.