The White House has confirmed US President Barack Obama was briefed on impending problems with his Obamacare website several months prior to its launch in October.
Senior administration officials heard recommendations made by consulting firm McKinsey & Co in March. They warned of many of the issues that arose once the website went live on 1 October.
On Tuesday, White House spokesman Jay Carney said no one anticipated the size and scope of potential problems.
The BBC says fewer than 27,000 people in 36 states are reported to have successfully enrolled in healthcare policies on the federal website since it launched.
About 79,000 managed to enrol using websites run by 14 other states and Washington DC.
On 14 November Mr Obama announced a reprieve of one year for those whose healthcare policies have been cancelled.
Repeated assurances were previously given by the president that citizens could keep their existing coverage, under Obamacare.