open enrollment

Open enrollment started Nov. 1 for Affordable Care Act health insurance marketplaces. Carmel Wroth/NPR hide caption

Open enrollment for Medicare begins Sunday and ads like this billboard inside California's John Wayne Airport are popping up. Marketing of Medicare plans is subject to new, stricter federal regulations this year. Leslie Walker/Tradeoffs hide caption

The Biden administration has opened up enrollment on all Affordable Care Act marketplaces, including on the federal insurance exchange, Healthcare.gov, until August. Many people will qualify for better or less expensive plans — or both. Healthcare.gov/Screenshot by NPR hide caption

The federal health insurance exchange, HealthCare.gov, has reopened until May 15 for new sign-ups; you can also switch to a different health plan on the exchange. But some states that run their own health insurance marketplaces have different rules. Joe Raedle/Getty Images hide caption

All health plans sold on HealthCare.Gov or one of state insurance exchanges are governed by Affordable Care Act rules. That means they have to provide comprehensive benefits to all applicants, regardless of their health or "preexisting conditions." But short-term plans and many others aren't bound by such restrictions. David McNew/Getty Images hide caption

Open enrollment is about to start for those buying private insurance off state or federal exchanges. PhotoAlto/Frederic Cirou/Getty Images hide caption

The deadline for the open enrollment period to sign-up on the federal exchanges for health care coverage is Dec. 15 Brakkton Booker/NPR hide caption

Lines like this one at a health insurance enrollment fair at the Ambrose Community Center in Bay Point, Calif., in 2014 may be longer this winter. Justin Sullivan/Getty Images hide caption