WASHINGTON (AP) - The Obama administration's health care website is stumbling on deadline day for sign-ups.

WASHINGTON (AP) The Obama administration's health care website is stumbling on deadline day for sign-ups.

Visitors to HealthCare.gov on Monday morning saw messages that the site was down for maintenance. At times the visitors were also directed to a virtual waiting room a feature designed to ease the strain on the site during periods of heavy use.

Administration spokesman Aaron Albright says the website undergoes "regular nightly maintenance" during off-peak hours and that period was extended because of a "technical problem." He didn't say what the problem was, but a statement from the Health and Human Services Department called it "a software bug" unrelated to application volume.

Albright said consumers seeking to sign up will be able to leave their email and "will be invited back when the system is available."