Top government information technology officials were set to testify before Congress on Wednesday that they were making headway on fixing HealthCare.gov, the troubled website used to sign up for President Barack Obama's signature health insurance program.
Obama has pledged that the website will work smoothly for most people by the end of the month — a critical deadline for Americans who need to sign up for insurance benefits that would start on Jan. 1.
He has come under fire after millions of Americans discovered they would lose their current health plans in spite of his oft-repeated promise that those who were happy with their insurance would not need to switch.
"We have much work still to do, but are making progress at a growing rate," Todd Park, chief technology officer at the White House, said in written testimony to the Republican-led House of Representatives' Oversight Committee.
Darrell Issa, the chairman of the committee, said the administration should have known the website did not work before it was launched.
"This wasn't a small mistake," Issa said as the hearing opened. "This was a monumental mistake to go live and effectively explode on the launch pad."
The 2010 Patient Protection and Affordable Care Act, or ACA, aims to provide health benefits to millions of uninsured Americans. It mandates that most Americans be enrolled for health coverage by March 31 or pay a fine.
The White House had pleaded with the committee to postpone Park's appearance, saying he needed to devote all his time to fixing the website. But the committee subpoenaed him.
Also slated to testify are Steven VanRoekel, the chief information officer at the White House budget office, and Henry Chao, the deputy chief information officer at the Centers for Medicare and Medicaid Services.
In his written testimony, Chao sought to address concerns about privacy and security of personal information used to sign up for insurance, and said the website meets "stringent privacy and security controls."
Chao also said the administration failed to test HealthCare.gov for the Web traffic volumes seen on Oct. 1, when it launched, accounting for technical problems.
"We now know that we underestimated the volume of users who would attempt to log onto the system at the same time, and therefore our testing did not include performance testing at the volume we experienced at launch," Chao said.