Insurers are getting faulty and incomplete data from the new U.S.-run health exchange, which may mean some Americans won’t be covered even after they sign up for an insurance plan.

While it’s not clear how widespread the problem is, the reports from industry consultants are the first hint that the technical troubles faced by consumers trying to enroll in health plans under the Affordable Care Act may also be hitting the insurers. The companies are receiving electronic files that can’t open or have so much missing information on new enrollees they’re unusable, the consultants said.

Some insurers have been forced to fix entries by hand, said Bob Laszewski, an insurance-industry consultant based in Arlington, Virginia.

“If we don’t see substantial improvement by the end of this week, then I would throw up the yellow flag,” said Dan Schuyler, a consultant advising states and insurers on the exchanges. “If we don’t see it in the next two to three weeks, it’s time for red flags. The concern is some people could get to Jan. 1, and not have coverage.”