The US president, Barack Obama, has that Americans will be allowed to keep cancelled health plans for an extra year, in a major climbdown after the troubled launch of his landmark reform.
In promoting plansd to expand health insurance to millions of Americans without cover, the president had promised that those happy with their existing coverage could keep it.
But, when the programme was launched, many people received notices that their policies were being cancelled as they were no longer compatible with the new rules, and replacement plans would cost more.
Compounding this surprise, the roll-out of the programme was undermined by an online marketplace for new, cheaper coverage plans that proved unable to meet demand and repeatedly crashed.
On Thursday, under pressure from politicians and falling poll numbers, Obama announced that policy cancellations would be postponed for a year while his policy problems were fixed.
Obama said that a measure to allow those who had insurance plans before Obamacare came in effect would be extended to those who bought them after its enactment.
"The bottom line is insurers can extend current plans that would otherwise be cancelled into 2014," he said,
"And the American people - those who got cancellation notices deserve and have received - an apology from me," Obama said, acknowledging several times that "that's on me."
"But they don't want just words," he said. "What they want is whether we can make sure that they are in a better place and that we meet that commitment."
While admitting that the online marketplace for Americans to find new health plans had had a "rough start", Obama warned his political opponents not to try to overturn the entire law.
"I will not accept proposals that are just another brazen attempt to undermine or repeal the overall law and drag us back into a broken system," he said.
Figures released on Wednesday showed only 106,185 people have been able to register for the programme, 1.5 percent of the number the administration had planned to recruit by the end March next year.