More than 670,000 people signed up for health coverage through the Affordable Care Act on Thursday, marking the busiest single enrollment day since the healthcare law’s coverage expansion began three years ago.
The record tally, announced by President Obama at his year-end news conference Friday, continues the strong enrollment this fall following Donald Trump’s Nov. 8 election victory.
And it underscored again the challenge that Trump and his Republican congressional allies face in repealing Obamacare, as the law is often called.
"More are signing up by the day," Obama told reporters in the White House briefing room.
The surge in sign-ups this week prompted the U.S. Department of Health and Human Services to extend the deadline for getting coverage that would begin on Jan. 1. The deadline for that coverage is now 11:59 p.m. PST on Dec. 19. The enrollment period runs through the end of January.
This enrollment period comes at a critical moment for the marketplaces and the health law that Obama signed in 2010.
The program has recorded historic gains over the last three years, as more than 20 million previously uninsured Americans gained health insurance, and the nation’s uninsured rate dropped to the lowest level ever recorded.
Congressional Republicans have pledged to vote to roll back the law early next year.
But the GOP has not yet advanced any alternatives that would protect the millions of people who now depend on health coverage through the law.
Many of these Americans have low incomes and rely on Medicaid, which has been expanded through the health law.
But about 11 million get commercial health plans through HealthCare.gov and similar state-based insurance marketplaces such as Covered California that were created through the law.
More than 80% of these consumers receive government subsidies to offset the cost of their premiums.
The Thursday tally incudes new and returning customers getting health plans through HealthCare.gov, the federal marketplaces serving 38 states.
It does not include enrollment on the remaining 13 marketplaces run by states, including California, and the District of Columbia.
Covered California, the nation's largest state marketplace, has also been seeing strong enrollment this fall. Like HealthCare.gov, Covered California extended its enrollment deadline for Jan. 1 coverage to Dec. 19.
12:43 pm: This post has been updated with additional background information