MINIMIZING THE CONFUSION

The problematic rollout of the health law known as Obamacare, which was passed in 2010 and survived legal challenges, helped send Obama's popularity ratings to record lows and stepped up Republican efforts to gut the law and use it against Democrats in 2014 congressional elections.

The more recent changes, which the administration has said are intended to show flexibility, have introduced a new element of confusion for consumers as well as the health insurance companies that have been pressed by the government to allow new members to pay, and even sign up, past January 1 for retroactive coverage. So far the industry has agreed to extend the first payment deadline to January 10.

"Health plans will continue to do everything they can to help consumers through the enrollment process and to mitigate potential confusion or disruption caused by all of these last-minute changes to the rules and deadlines," said Robert Zirkelbach, spokesman for American's Health Insurance Plans, an industry trade and lobbying group.

"Navigator" groups that have been chosen by the government to help people sign up said they were receiving panicked calls from consumers who mistakenly thought they would be shut out of any coverage in 2014 if they didn't sign up now.

"They think if they don't enroll today they're going to be penalized," said Sandra Luz, lead navigator at the Community Council of Greater Dallas. Luz said the group's office was prepared to stay open late on Tuesday to accommodate more calls and walk-in visits and would work over the holiday week with the exception of Christmas Day and New Year's Day.

The Affordable Care Act requires most Americans to be enrolled in coverage by March 31 or face penalties that start at $95. This week's deadline, which had already been moved to December 23 from December 15, applied to coverage starting on January 1.

"A ton more people are calling in right now, and this is from people who haven't been doing this any earlier. There really are many more people who are just looking at this for the first time thinking, 'Oh my goodness, I need to get this done now,'" said Ari Epstein, a navigator for SER National in Waukegan, Illinois.

He said he worked with one consumer on health plan options until 11 pm on Monday.

"What's really taking the most time isn't the issues with the site that I've seen, it's folks who have questions about coverage, and the specifics of any respective plan that I don't have answers for. The wait times for the respective providers can be two hours or two and a half hours," he said.

Several state-run exchanges have also moved their enrollment deadlines. New York and California, two of the largest, added a one-day grace period similar to the federal insurance marketplace.

Massachusetts said on Tuesday it would allow sign-ups until December 31 given heavy volume and technical problems that have hampered its exchange. Rhode Island, Oregon and Maryland had already extended their deadlines beyond Christmas.