The move was the latest in a series of deadline changes, exemptions and clarifications that have confused insurers and many Americans and opened the administration to increasing criticism from Republicans who have opposed the Affordable Care
Act from the start and have repeatedly tried to overturn it.
It was not clear on Tuesday how many people would be affected, or how consumers would prove that website errors had prevented them from signing up by the deadline on Tuesday night.
The announcement itself was vague, saying only that if website problems had prevented any consumers from enrolling, they might qualify for what the government has called “a special enrollment period.” The administration did not say how long that would last. Nor did it define what website errors might be involved.
Republicans said the announcement — coming a day after the federal website recorded more than two million visits — showed that President Obama (Soetoro) was desperate to increase enrollment, widely seen as a measure of the success of the health care law.
For their part, administration officials said the move was a common-sense response to heavy traffic on the website, which they cited as evidence of a huge need for more affordable insurance. Some 48 million Americans are uninsured. Many could qualify for subsidized coverage under the Affordable Care Act.
Tara McGuinness, a White House spokeswoman, said the administration was not providing “a blanket extension,” but was offering to provide “assistance to individuals on a case-by-case basis.”
And Kurt DelBene, the new troubleshooter for the site, said it was performing well. “With the highest volumes we have seen to date, response time is fast, and the error rate is low,” he said.
The move did not mollify insurers who have grown concerned as new problems have erupted since the rollout on Oct. 1 and are worried about how they will be able to provide coverage for everyone who wants it by Jan. 1, when that coverage is supposed to go into effect.
“The goal posts keep moving,” William G. Schiffbauer, a lawyer who represents insurance companies, said Tuesday evening. “That raises questions about whether insurers can collect premiums in a timely manner to pay claims from doctors and hospitals.”
“The latest step creates confusion for consumers and insurers,” he added.
Insurers said that Tuesday’s action, combined with several recent unexpected shifts in federal rules and policy, made it harder for them to predict the number and characteristics of new subscribers. That, in turn, makes it harder for them to predict their costs and complicates efforts to set prices for their products.
In general, insurance companies say they need substantial numbers of healthy people to balance the financial risks of covering older Americans who require more medical care.
The open enrollment period continues to March 31. People who select health plans on the federal exchange starting Wednesday and continuing through Jan. 15 will generally be entitled to coverage that takes effect on Feb. 1, provided they pay their share of the first month’s premium before then.
The new offer to consumers who have had trouble with the website followed the last-minute surge of interest among people seeking coverage, and the administration hailed what it described as “amazing interest” in new health insurance options.
The original deadline for coverage starting Jan. 1 was Dec. 15. On Nov. 22, the deadline was extended to Dec. 23. On Monday, the White House provided a 24-hour grace period, to 11:59 p.m. on Tuesday.
Then on Tuesday, in a bid to ensure coverage for all who want it, the administration provided details of the “special enrollment period” for some people — but not all — who miss the deadline.
“If you weren’t able to enroll in an insurance plan by Dec. 23 because of problems you had using HealthCare.gov, you still may be able to get coverage that starts Jan. 1,” the administration told visitors to the website in a message posted on the health insurance blog at HealthCare.gov. The message also highlighted the assistance available to shoppers.
“Couldn’t enroll by December 23?” it said. “We can still help you get covered.”