Children under 12, who cannot be vaccinated, can show a negative test to attend.

Broadway’s theater owners and operators, citing the ongoing dangers of the coronavirus pandemic, said Friday that they have decided to require that theatergoers be vaccinated against Covid-19 and wear masks in order to attend a performance.

The policy, announced just days before the first Broadway play in more than 16 months is to start performances, allows children ineligible for vaccination to attend shows if tested for the virus.

But some performing arts venues in New York say they will go even further: the Metropolitan Opera, which hopes to reopen in late September, and Carnegie Hall, which is planning to reopen in October, are not only planning to require vaccinations, but also to bar children under 12 who are not yet eligible to be vaccinated.

The new vaccination requirements for visitors to New York’s most prominent performing arts venues come as the highly contagious Delta variant has caused Covid-19 cases to rise, leading the Centers for Disease Control and Prevention to recommend that vaccinated Americans in virus hot spots resume wearing masks indoors.

The Broadway rules, which will be in place at least through October and apply to all 41 Broadway theaters, require that audiences wear masks, except when eating or drinking.

The Broadway vaccination mandate will apply not only to audiences, but also to performers, backstage crew and theater staff.

There will be limited exceptions: “people with a medical condition or closely held religious belief that prevents vaccination,” as well as children under 12, can attend with proof of a recent negative coronavirus test.

Although Broadway, which has a number of shows that depend on ticket buying by families with children, has decided to allow those under 12 to attend if tested, the Met Opera, which draws fewer young children to most of its productions, is taking a more restrictive approach.