Midnight tonight marks the end of Obamacare’s first open enrollment period, but those looking to sign up on deadline day may have missed their chance.

The federal government’s healthcare website, Healthcare.gov, is no longer accepting new applications because of technical issues, the AP reports. The site went down for a few hours Monday morning, and delays continued even after it came back up.

A message appearing to users in the early hours initially indicated that it was out of service for maintenance issues, but a later message indicated the site was experiencing heavy traffic. Users were directed to a virtual waiting room where they would be told when they could begin the process.

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The site received about 2 million visitors a day over the weekend, an increase of about half million from the previous week, the AP reports.

This is not the first time there have been problems with the site. The launch of the site in October 2013 was hampered with many technical issues, which may have contributed to the low initial enrollment rate.

Six million people have already signed up for health coverage under the Affordable Care Act. The Centers for Medicare and Medicaid, which is responsible for implementing the law, anticipates at least 7 million will be enrolled by the deadline.

Although March 31 is the last official day to sign up, millions of Americans may be eligible for extensions. The federal government will accept paper applications until April 7 for those who couldn’t finish enrollment because of technical glitches, natural disasters, domestic abuse, or other reasons depending on their circumstance or state rules.

Massachusetts extended the enrollment deadline last Thursday to April 15 following glitches in the state’s own health insurance website.

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