"We realize that many consumers who are seeking coverage in January may have experienced frustration with the site," Julie Bataille, spokeswoman for the Centers for Medicare and Medicaid Services, told reporters. "This extension will allow consumers to review plan options, to talk with their families... and to enroll in a plan."
According to HHS, the change applies only to the 36 states where consumers are using HealthCare.gov. The 15 state-based insurance marketplaces can make their own decisions about the initial enrollment deadline. On Thursday, California moved its deadline from Dec. 15 to Dec. 23 as well.
Consumers must pay their first premium by Dec. 31 for their coverage to begin on Jan. 1, Bataille said.
When asked if the administration was also considering extending the final enrollment deadline beyond March 31, 2014, as some Democratic senators have urged it to do, Bataille said: "Not at this point."
"We think that six-month-long open enrollment window is a significant amount of time for consumers to get information, understand their plan options and to be able to make the decision that is right for them," she said.
The administration consulted with insurance companies before making the change, Bataille said, and officials are confident that companies will have enough time between Dec. 23 and Jan. 1 to process applications and prepare to start coverage.
"This was done in consultation with them to make sure that consumers would be able to access coverage beginning Jan. 1," Bataille said.
UPDATE 2:34 p.m. ET
America's Health Insurance Plans, the industry's top lobbying group, issued the following statement about the extension:
"It makes it more challenging to process enrollments in time for coverage to begin on January 1," AHIP spokesman Robert Zirkelbach said.