Open enrollment on the federal health law’s marketplace ends Friday, and most people who want a plan for next year need to meet the deadline.

But some consumers who miss the cutoff could be surprised to learn they have the opportunity to enroll later.

“While a lot of people will be eligible … I am still worried that a lot of consumers won’t know it,” said Shelby Gonzales, a senior policy analyst at the Center on Budget and Policy Priorities.

Under the health law, people are entitled to a special enrollment period (SEP) when they have specific changes in their lives, such as losing other health insurance, getting married or having a child, or when they have a change in income that affects their eligibility for premium tax credits or cost-sharing reduction subsidies. Those special enrollment periods generally last at least 60 days.

Other circumstances can also qualify customers for a special enrollment period. But this year, consumer advocates are focused on two that could affect a substantial number of people: consumers whose 2017 marketplace policies are being discontinued in 2018 and people affected by the hurricanes that ravaged Texas, parts of the Southeastern United States and Puerto Rico.

It’s not clear how many consumers this will affect. In past years, people who sign up during an SEP made up a tiny fraction of overall marketplace enrollment. In the spring of 2016, 11.1 million people had a marketplace plan. Meanwhile, roughly 1.6 million signed up through a special enrollment period during 2015, according to the federal Centers for Medicare & Medicaid Services (CMS).

The majority of people who use a special enrollment period do so because they’ve lost coverage under another plan. This applies to people who lose their job-based coverage as well as those with marketplace plans whose insurer discontinues their plan for the upcoming year.

Between 2014 and 2018 the average number of issuers per state declined from 5 to 3.5, according to the Kaiser Family Foundation. (KHN is an editorially independent program of the foundation.) Several big name companies, including Anthem, Aetna and Humana, dramatically pulled back in their 2018 offerings.

A growing proportion of people will likely qualify for SEPs now because of a loss of marketplace coverage, insurance analysts say.

People who are eligible for that special enrollment period have up to 60 days after their coverage ends on Dec. 31 to sign up for a new marketplace plan. Meeting the regular Dec. 15 sign-up deadline is preferable because it allows coverage to start Jan 1. But eligible people who miss that date can apply through the marketplace for an SEP that will allow them to sign up until the end of February.

Even if the marketplace automatically re-enrolls customers in a plan that’s similar to the one that ended, they’re entitled to an SEP to pick a new plan, said Karen Pollitz, a senior fellow at the Kaiser Family Foundation.

But people shouldn’t count on getting a clear explanation of what the SEP is or how it works, said Pollitz, who has reviewed the consumer notices related to plan discontinuations.

“The notices are not what they could be,” she said.

Gonzales concurs.

“The bottom line here is many consumers experienced a discontinuation of their plan this year,” she said. “Notices are complicated, and these consumers in particular are going to get several notices which may result in more confusion, and it will not be easily understood by many what an SEP is or how and/or when to activate it.”

This year, there are also special enrollment periods for people who were affected by the hurricanes that slopped across all or parts of Texas, Florida, Georgia, Puerto Rico and elsewhere last fall.

The special enrollment period for 2018 applies to people who live in or move from counties designated by the Federal Emergency Management Agency as hurricane disaster areas. It gives them an extra two weeks, from Dec. 16 to Dec. 31, to sign up for January coverage. Officials said they’ll consider extending the timeframe if necessary.

To take advantage of the special enrollment period, people must request it through the healthcare.gov call center. They’ll be asked to attest that they resided in an affected area, but they won’t have to provide proof.

Consumer advocates who work on outreach for enrollment and help people sign up for coverage aren’t yet talking up the SEPs, said Gonzales.

“They want one clear message for everyone: Open enrollment ends Dec. 15,” she said. Starting Dec. 16, these groups will start getting the word out for people who have missed the deadline and may not realize they may have other options.

Please visit kffhealthnews.org/columnists to send comments or ideas for future topics for the Insuring Your Health column.