Administration officials said Monday that some visitors to ObamaCare's federal enrollment site would experience outages, slow response times or messages to try again later during the month of December.
The Centers for Medicare and Medicaid Services (CMS) delivered the message in the latest attempt to downplay expectations surrounding Nov. 30, the administration's self-imposed deadline for fixing HealthCare.gov.
But Bataille acknowledged that some people would still experience "periods of suboptimal performance" by the system due to either heavy traffic or technical issues that are still being addressed.
"The system will not work perfectly on Dec. 1, but it will work much better than it did in October," Bataille said.
The comments came after the White House said the repair effort is "on track" to meet the Saturday deadline thanks to steady technical improvements.
Spokesman Josh Earnest said the site remains a "work in progress" but touted metrics showing that its error rate and page load times are now far below where they started.
The administration has staked its healthcare rollout on expanding the system's user capacity and addressing site errors by the end of the month.
Both supporters and opponents of the Affordable Care Act are closely watching the deadline, which helped the White House tamp down a political firestorm over the exchanges' troubled debut.
Both groups know that if the site cannot recover by next month, its dysfunction will plunge the administration into another political crisis.
The month of October dealt a serious blow to President Obama's poll numbers and erased Democrats' advantage coming out of the government shutdown. Opponents see any further missteps on healthcare as crucial fodder for next year's midterm elections.
Further technical problems at HealthCare.gov would also threaten the wave of enrollments expected in the first three weeks of December, putting consumers at risk of lacking coverage they need on Jan. 1.
Administration officials have strongly challenged this possibility. Former White House budget director Jeff Zients, now in charge of fixing the healthcare site, said last week that the system will "reach everybody we need to reach" in December, thanks to ongoing fixes.
Part of that effort is building the system's capacity to handle user traffic. HealthCare.gov was designed to handle 50,000 concurrent users but has only managed about half that number since Oct. 1.
The CMS said that, by this weekend, the site will be able to handle a full user load and will have a "queuing" system in place in case of traffic above that threshold. Under that program, users can either wait to be granted access or choose to receive an email when traffic dies down.
But not all parts of the system are working well, even two months after the exchanges launched.
HealthCare.gov has struggled to transmit accurate application information to insurance companies in forms known as 834s. The CMS did not provide an update Monday on that fix, suggesting that officials are still struggling to ensure the forms are correct.
The 834 issue highlights the range of problems that could arise for HealthCare.gov even if the site's user experience improves.
The system relies on a series of complicated interactions with insures as well as federal agencies to determine eligibility for premium tax credits and Medicaid.
Critics have charged that the broken system could not be trusted to accurately make eligibility determinations, though it is unclear whether this is true.