CHICAGO — Anticipating heavy traffic on the government’s health care website, the Obama administration extended Monday’s deadline for signing up for insurance by a day, giving Americans in 36 states more time to select a plan.

Colorado, one of 17 states with ther own health care exchange, did not extend its deadline but will try to be lenient with latecomers, said Ben Davis, Colorado Connect for Health spokesman.

The federal move was the latest in a series of pushed-back deadlines and delays that have marked the rollout of the health care law.

But federal officials urged buyers not to procrastinate.

“You should not wait until tomorrow. If you are aiming to get coverage Jan. 1, you should try to sign up today,” said Julie Bataille, a spokeswoman for the federal agency in charge of the overhaul.

Bataille said the grace period — which runs through Tuesday — was being offered to accommodate people from different time zones and to allow for any technical problems that might result from a last-minute rush of applicants.

The healthcare.gov site had a disastrous, glitch-prone debut in October but has gone through extensive improvements to make it more reliable and increase its capacity, and the administration said the system was running well Monday.

By the afternoon, the site had received a record 850,000 visits, five times the number logged by the same time last Monday, the administration said. Bataille said the system was handling the volume with error rates of less than 1 in 200 and response times at less than one second.

The administration was careful not to characterize Tuesday as a new deadline or an extension, likening the move instead to the Election Day practice in which people who are in line when the polls close are still allowed to vote.

The Obama administration is hoping for a surge of year-end enrollments to show that the technical problems were merely a temporary setback.

But the grace period may have been a tacit acknowledgement that the website remains vulnerable to heavy traffic. What’s more, the delay offered critics of Obamacare another opportunity to argue that the law still isn’t working and that President Barack Obama keeps changing the rules.

Roger Colyn, 60, of Des Moines, Iowa, was happy when he left his Monday morning appointment with a state enrollment navigator. She helped him sign up for a “silver” plan that will cost him $10.79 of monthly premiums after government aid is factored in.

Others said they will let the date pass without making a decision.

“I’m in no hurry, though it’d be nice to be able to visit a doctor without stress,” said Kyle Eichenberger, an uninsured 34-year-old from Oak Park, Ill., who said he hit a wall on the website when he first tried to enroll early on.

The government’s original deadline already had been pushed back a week because of the website problems. The extra day will add to the already daunting administrative problems for insurance companies, such as inaccuracies on applications, said industry consultant Robert Laszewski.

“Insurers would like to have two to three weeks to process applications. Now they’re going to have a week, less one more day,” he said. “When the day is done, it doesn’t help.”

Obama said on Friday that more than 1 million Americans had enrolled for coverage since Oct. 1. The administration’s estimates call for 3.3 million to sign up by Dec. 31, and the target is 7 million by the end of March. After that, people who fail to buy coverage can face tax penalties.

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Obama signs up in symbolic gesture •HONOLULU — He won’t use it, and he didn’t actually sign up for it himself, but President Barack Obama has enrolled for health coverage through the new insurance exchanges.

Announcing his enrollment Monday, the White House called it a symbolic show of Obama’s support for the fledgling exchanges where millions of Americans must buy insurance or face a penalty. Ironically, it also served as a reminder of just how complex and sometimes daunting the process can be.

Obama, like so many other Americans, couldn’t use the website.

“The complicated nature of the president’s case required an in-person sign-up” by staff members, the White House said.

White House officials noted that for security reasons, the president’s personal information is not readily available in government databases that the exchanges use to verify identities and check eligibility for tax subsidies.

Obama selected a “bronze” plan, the least-expensive plan available for someone his age. The White House said the plan Obama chose will cost him less than $400 a month. The president’s wife and daughters, who already have health care, did not enroll.

As commander in chief, the president receives his health care through the military, so his new coverage will go unused. Rather, the move fulfills a commitment to personally participate that Obama made in 2010, when he signed into law the Affordable Care Act. The Associated Press