NEW YORK — When do I still need to wear a mask?

It depends, mostly on whether or not you're vaccinated.

If you're fully vaccinated, the latest guidance from the U.S. Centers for Disease Control and Prevention says you no longer need to wear a mask or physically distance in most situations. That includes when you're outside and in many indoor spaces like restaurants, though you still need to follow any local or business rules. 

Americans also still need a mask when traveling, including on buses, subways and planes and at airports. The guidance on masks will differ by country.

Some experts say the CDC is relaxing its recommendations too soon.

Part of the concern is that there's no way to tell who's vaccinated, so unvaccinated people could claim they got the shots and go maskless, said David Holtgrave, dean of the School of Public Health at University at Albany. That could cause cases to rise.

"A central mistake in public health is easing up infectious disease control efforts just before crossing the finish line," he said.

Vaccinated people might also prefer to continue wearing their masks. Though chances are low, it's still possible to get infected, even if symptoms are likely to be mild or nonexistent. 

That's why the CDC's guidance says vaccinated people should put their masks back on and get tested if they end up developing symptoms. 

There are other exceptions. Masks are still needed in select settings including hospitals and nursing homes. And if you have a weakened immune system because of a health condition or medications, the agency says to talk to your doctor before shedding your mask, since vaccines generally don't work as well in people with weak immune systems. 

People are considered fully vaccinated two weeks after their last required shot. 

If you're not yet fully vaccinated, the CDC still recommends masks in most places outside your home. That includes indoor public spaces, crowded outdoor events like concerts and small outdoor gatherings that include other unvaccinated people.

When you're outdoors alone or with people from your household, the agency says unvaccinated people don't need masks. 

Since children younger than 12 aren't yet eligible for COVID-19 shots, they should continue to wear masks indoors outside the home and in most public places like other unvaccinated people.