(CNN)More people signed up for Obamacare coverage on the federal exchange during open enrollment this year -- the only increase under the Trump administration, which has long sought to eradicate the landmark health reform law.
More than 8.2 million people selected plans for 2021 in the 36 states using healthcare.gov, according to preliminary data released Friday by the Centers for Medicare and Medicaid Services. The Affordable Care Act's increase in popularity comes as the Supreme Court considers whether to overturn the law, with a ruling expected in the first half of next year, and as the country finds itself in the worst period yet of the coronavirus pandemic.
Sign ups are slightly less than last year's 8.3 million figure, but that data included New Jersey and Pennsylvania, both of which shifted to their own marketplaces for 2021 coverage.
Removing these states, as well as Nevada, which set up its own exchange for 2020, plan selections increased by 6.6% from 2020, 6.3% from 2019 and 2.2% from 2018, the agency said.
"The significant growth this year is a reflection of the impact of COVID-19 on the American people and the important role the Affordable Care Act played in strengthening the safety net," said Josh Peck, a former Obama administration official and co-founder of Get America Covered. "This is the first open enrollment period following an economic contraction."
Health policy experts expect that some Americans who lost their job-based coverage as a result of the coronavirus pandemic are shifting to Affordable Care Act policies. Enrollment in Obamacare remained fairly steady, though typically it drops over the course of the year. More people signed up during special enrollment periods than usually do.
The Trump administration pointed to a total of an 8% decrease in premiums, on average, for the benchmark plan over the past three years and an increase in the number of insurers participating on the exchanges.
Obamacare enrollees renew coverage
Some 6.4 million current Obamacare enrollees selected plans or were automatically re-enrolled for 2021, up an unprecedented 10.6% from the year before.
However, the number of new people signing up fell to 1.8 million, down 5.4% compared to last year.
Five states saw double-digit growth in sign-ups, with Texas leading the way at 15%. Eight states experienced declines, ranging from -1% to -7%.
Open enrollment on the federal exchange ran from November 1 to December 15, half the time it did under the Obama administration.
Just how many Americans ultimately choose coverage for 2021 on the Affordable Care Act exchanges won't be known until early next year. Some of the 14 states, plus the District of Columbia, that run their own exchanges have longer open enrollment periods that stretch into January.
Maryland reported this week that a record number of residents signed up for 2021 coverage through its exchange. Just over 166,000 Marylanders selected plans, up 4.5% from the prior year. Open enrollment ended there on December 15.
State officials attributed the increase in part to the fact that Maryland offered residents the ability to sign up for Obamacare coverage during a special enrollment period this year. Nearly 33,000 people took advantage of the opportunity.
President Donald Trump opted not to reopen the federal exchange this year, though those who lost their job-based coverage could sign up for Obamacare plans within 60 days.
Enrollment isn't considered final until policyholders make their first premium payment.
Supreme Court determining Obamacare's fate
Enrollment is taking place as Supreme Court justices are considering the fate of the landmark health reform law. The justices heard oral arguments in a case seeking to invalidate the Affordable Care Act on November 10.
A coalition of Republican state attorneys general led by Texas and joined by the Trump administration are arguing that the individual mandate is unconstitutional because Congress reduced the penalty for not having health insurance to zero as part of the 2017 Republican tax cuts -- and that the entire law must fall as a result.
Chief Justice John Roberts and Justice Brett Kavanaugh suggested that it wasn't the Supreme Court's role to toss out the whole law even if one or more provisions are deemed unconstitutional, signaling the Affordable Care Act will survive the court challenge.