WASHINGTON (AP) — The White House says the government'sHealthCare.gov exchange plan enrollment website received 375,000visitors on Monday between midnight and noon.

That's a surge in use on the first business day since Obamaadministration officials declared that the government's beleagueredonline insurance service is now better equipped to meet users'needs.

White House spokesman Jay Carney said at a press conference thatthe White House was expecting a rush of traffic on Monday.

The HealthCare.gov enrollment system first opened to the publicOct. 1.

Julie Bataille, a spokeswoman for the Centers for Medicare &Medicaid Services, said at a separate CMS press briefing thatvisitor traffic has been about twice as high as the level oftraffic HealthCare.gov has been averaging on Mondays from midnightto noon.

HealthCare.gov managers activated a site feature called a"queue," or "waiting room system," when they found that heavytraffic was starting to hurt site performance, Bataille said. Thesystem requires excess users to wait before using HealthCare.govplan research and enrollment tools, to protect the performance ofthose tools.

CMS officials have said that the enrollment system should now beable to handle 50,000 users at the same time.

On Monday, however, system managers found they needed toactivate the waiting room system when user volume was somewherebetween 30,000 and 40,000, Bataille said.

Also during the CMS press briefing, Bataille said:

• CMS has determined that one bug involving handling of SocialSecurity numbers has been causing about 80 percent of the reportedproblems with issuance of the so-called "834" plan enrollmentcompletion messages. Bataille was unable to say how many 834message problems site users have actually experienced.
• CMS will cope with the lack of a complete back-office systemfor administering Patient Protection and Affordable Care Act(PPACA) exchange plan premium subsidies by temporarily using anexisting Medicare system to administer the payments.
• At least one insurer -- Blue Cross and Blue Shield of Florida-- is expanding a new pilot program that lets insurers calculatesubsidies for consumers and enroll consumers who are eligible forthe subsidies directly, rather than forcing the consumers to enrollthrough HealthCare.gov. CMS officials said Sunday that 16 insurersin three states are participating in the direct-enrollment pilotprogram.