These days it seems like everybody following Obamacare is talking about the 834s. Those are the personal data files that healthcare.gov sends insurance companies, in order to notify them of new enrollees. The data has been prone to errors and that's a real problem. You can't get new coverage if the insurer doesn't have some basic information about you—your full name, Social Security number, and so on. Prevalent errors could lead to disarray in the new year. On January 1, some people who completed the enrollment process through healthcare.gov could show up at a pharmacy, physician office, or hospital only to discover they had no active coverage. Something like this happened in 2006, when the Bush Administration launched Medicare Part D.

But the 834 problem is fixable and, according to multiple sources in the public and private sectors, it is being fixed. In fact, one administration official tells The New Republic that preliminary estimates, just now becoming available, suggest the error rate has fallen from one in four during October to one in ten now. And most of those are files insurers received with errors, as opposed to files insurers never received. Plenty of work remains—namely, completing repairs that reduce the error rate further and dealing with the flawed data insurers have already received. But the administration is working with insurers and contractors on both issues.

Some background: The figure 834 is actually shorthand for “834 EDI Transmissions" or "834 EDI Transactions," which consist of personal data organized in a way that insurance companies can decipher and process electronically. The 834s have been around for a long time, sent by employers, brokers, and government in order to arrange new coverage for individual employees, consumers, and beneficiaries. If you get private insurance through a large company, for example, somebody working in the human resources department once submitted an 834 with information about you, so that an insurer could add you to its rolls and send you an insurance card.

Healthcare.gov communicates with insurers the same way. Once you’ve used the site and picked a plan, the system sends an 834 with your information to whatever insurer you've chosen. (Actually, as I understand it, the site sends the data once a day in batches.) The carrier then takes the information, signs you up, and sends you a bill for your first month’s premium. That last part is important. If you don’t pay that first premium, you won’t have insurance come January 1. That’s obviously a big deal, particularly for people with chronic health problems that require constant medication.

Until a few weeks ago, almost nobody outside the insurance industry had even heard of 834s. Then healthcare.gov opened for business—and the insurers discovered the 834s from the site contained errors at an alarming rate. Data was missing or in the wrong field: Some files had transposed parents and children, for example. Among the first to write about this problem was Robert Laszewski, the insurance industry consultant and widely read blogger. It also got attention in the New York Times and Wall Street Journal, and from Sarah Kliff in the Washington Post. If you want a fuller explanation of the forms and how companies use them, Kliff’s backgrounder at the Post’s Wonkblog remains the most accurate and thorough guide I’ve seen.