White House press secretary Jay Carney (REUTERS/Kevin Lamarque) White House press secretary Jay Carney (REUTERS/Kevin Lamarque)

The federal health insurance marketplace received 375,000 visitors by noon Monday, HealthCare.gov tweeted, triggering a new system informing some users they can either try again later or receive an e-mail when the system is easier to navigate.

White House press secretary Jay Carney told reporters that the administration "absolutely anticipated that on this day in particular" the site "would see a surge in visitors" because it was the first workday after it announced the system was mostly fixed.

The administration announced Sunday it had met its self-imposed Nov. 30 deadline to expand the site's capacity to allow 50,000 users at once, which equates to roughly 800,000 visitors a day. Officials including Jeffrey Zients, who is overseeing the system's fix, warned that at times the use would exceed the site's capacity and people would be forced to wait.

In an op-ed published Monday in USA Today, Secretary of Health and Human Services Kathleen Sebelius urged Americans to visit the site in "off-peak" hours in the morning or night, despite the fact that it had experienced a "dramatic improvement" over the past two months.

Carney added that the "improved queuing system" gives consumers a chance to "return to the site and enroll more effectively and efficiently, and that way [makes] the whole operation more effective and smooth."