Americans vaccinated against Covid-19 no longer need to wear masks outdoors, except at crowded events, US government health authorities have said.
Under the newly released guidance from the Centers for Disease Control, fully vaccinated people can eat, walk or attend small gatherings outside without a mask.
"If you are fully vaccinated, you can start doing many things that you had stopped doing because of the pandemic," the government body said in a statement.
Masks are still considered necessary for vaccinated people if they are at concerts, parades or large sporting events, even when outdoors, the CDC said.
Indoor activities remain under a masks recommendation. This includes movie theatres and even "uncrowded" indoor shopping centres and museums, the CDC said.
The CDC stressed that its newly relaxed guidance only applies to people who have had their full vaccine doses and are two weeks past the final shot.
More than half of all US adults have now received at least one of two vaccine doses.
The surging rate of people seeking out vaccines has begun to taper, but new Covid-19 cases are also falling.
US President Joe Biden hailed the "stunning" progress that the United States has made in the fight against the pandemic, as he addressed the nation from the White House.
"While we still have a long way to go in this fight, a lot of work to do in May and June to get us to 4 July, we've made stunning progress because of all of you, the American people," Mr Biden said, referencing Independence Day as a milestone goal in the fight against the virus.
"Cases and deaths are down - down dramatically from where they were when I took office."
The US government announced on Monday it would be sending up to 60 million doses of the AstraZeneca vaccine abroad, after critics had accused Washington of "hoarding" the jab.
The vaccine is not authorised in the country and will likely not be required to vaccinate Americans.
Mr Biden said the science behind the new mask guidance was supportive of the move.
He urged those who have not got a vaccine yet to do so as soon as possible, especially younger people.
The bottom line was clear, he said, in that if a person is vaccinated, they can do more activities safely.
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