While consumers who click onto HealthCare.gov will see a cleaner, simpler application page, insurers still have headaches. They interact with the website’s so-called back end, which is supposed to tell carriers who signed up and to pay out Obamacare’s subsidies.

That part still doesn’t work as it should. Insurance industry sources say the Centers for Medicare and Medicaid Services (CMS) had sorted through about 80 percent to 85 percent of existing accounts to make sure its records match those of insurers. The agency is not likely to be done by Saturday; the latest best-case scenario is for the job to be finished by Dec. 15.

The date is key because anyone currently covered who doesn’t either re-enroll or pro-actively opt out will automatically be re-enrolled in the same plan or the closest match for 2015. But with all the gaps in the system, consumers could find themselves in the wrong plan — or even enrolled in more than one plan. Nor will the health plans always know promptly if a customer dropped one plan and chose another (even though the “834s” — those initial enrollment files that nobody had ever heard of until they gummed things up last year — are pretty reliable now).