Outside contractors testified last week that there wasn't sufficient time to test the complex online enrollment system, which froze the day it was launched, Oct. 1.
The website is supposed to be the online portal to coverage for people who don't have health plans on the job. Its audience is not only uninsured Americans but those who already purchase coverage individually.
Under the law, middle-class people can qualify for tax credits to make private health insurance more affordable, while low-income people will be steered to Medicaid in states agreeing to expand that safety net program.
Associated Press writer Juliet Williams in Sacramento, Calif., also contributed to this report