More than one million people had logged on to the site by 5 p.m., officials said, five times more than the previous Monday. The flood of visitors quickly triggered a backup queuing system that invites users to come back during less busy times. More than 60,000 people provided an email address on Monday to get invitations to return, officials said.
The high volume of visitors also prompted White House officials to abruptly establish a 24-hour grace period that will effectively extend the deadline, allowing those who sign up on Tuesday to still receive coverage from Jan. 1.
Officials compared the last-minute decision to the kind often made by election officials to keep a polling place open late into the night to accommodate voters already in line at closing.
The grace period was the latest example of the administration’s willingness to fiddle with deadlines that once seemed set in political concrete. The botched rollout of the website has forced the White House to adjust its plans repeatedly in an attempt to accommodate users and avoid further examples of signs that the program is not ready for prime time.
“We have taken steps to make sure that those who tried to enroll today, but had delays due to high traffic, have a fail-safe,” said Julie Bataille, a spokeswoman for the federal Centers for Medicare and Medicaid Services.
“People are having a really difficult time getting through,” David Oscar, an insurance broker in Fairfield, N.J., said Monday. He said frustrated clients were calling to say the website was sluggish. “My phone has been burning up. It’s the worst time of year to start this, and all these people who need coverage have so many other things that they’re doing.”
Even so, administration officials said there would be no more extensions. After Tuesday, people who sign up for insurance through HealthCare.gov should not expect to have coverage at the beginning of 2014, they said.
President Obama’s aides are bracing for Republicans to seize on stories of people whose insurance was canceled because of the Affordable Care Act and who were unable to find a replacement by Jan. 1. Some of those people may appear at a hospital, a doctor’s office or a pharmacy and be told that they no longer have coverage.
“While the holiday surprises have become commonplace, the latest extension is another disappointment for the ‘most transparent administration in history,’ ” Representative Fred Upton, Republican of Michigan, the chairman of the House Energy and Commerce Committee, said in a statement. “As we celebrate Christmas and prepare to ring in the new year, we continue to ask, what’s next?”
Mr. Obama, vacationing in Hawaii with his family, offered a symbolic gesture to people who are using the government’s health care site to get insurance: White House officials announced Monday that the president had enrolled in a health insurance plan over the weekend by using the District of Columbia’s website.
The president and his family receive health care through the military. But administration officials said they hoped that Mr. Obama’s gesture would set an example for many of the uninsured they were urging to sign up before the deadline.
Even though Mr. Obama will not actually use his new plan, a White House official said, “he was pleased to participate in a plan as a show of support for these marketplaces, which are providing quality, affordable health care options to more than a million people.”
The president opted for a bronze plan, one of the less expensive options on the HealthCare.gov site.