The Biden administration plans to reopen enrollment in many of the Affordable Care Act marketplaces, both to help those who may have lost health insurance during the pandemic and to offer coverage to those who did not have any and now want it. The move will be announced Thursday as part of an executive order describing administration policies on shoring up health insurance coverage, according to three people familiar with the details.

The so-called special enrollment period is intended to help people who have lost coverage in the past year, but it will be open to those who want health insurance for any reason, in the 36 states that use The decision was reported earlier by The Washington Post.

Typically, Americans without a special circumstance can buy Obamacare insurance only during a six-week period in the fall, a restriction meant to encourage people to hold coverage even when they are healthy. The sign-up period for this year’s coverage ended in mid-December, with enrollments only slightly higher than they were last year. But the Trump administration did little to advertise it. The Biden administration plans to have a large marketing campaign to announce the new opportunity and encourage people to enroll in health plans, two of the people said.

The insurance industry, which usually supports tight limits on insurance enrollments, is backing the extra enrollment period. Around 15 million Americans are uninsured and eligible for marketplace coverage, according to a recent analysis from the Kaiser Family Foundation. Most would qualify for some form of financial assistance if they bought such coverage — and about 4 million could sign up for a high-deductible plan that would cost them nothing in premiums.

“For the 4 million people who could be getting free coverage who are instead uninsured — that, to me, is screaming out for outreach,” said Cynthia Cox, a vice president at the foundation and a co-author of the analysis.

It remains unclear how many people lost health insurance last year because of the pandemic, but most working-age Americans receive coverage through their employers, and millions have lost jobs.

Enrollment in Medicaid, the public health insurance program for the poor and disabled, has grown substantially during the pandemic. And consumer advocates say there are also many Americans who were uninsured before but might want coverage now because of the public health crisis. Several states that run their own marketplaces established special enrollment periods last year and saw increased sign-ups.