WASHINGTON — A federal judge in Florida struck down the federal mask requirement on airplanes, trains, buses and other public transportation on Monday, less than a week after the Centers for Disease Control and Prevention had extended it through May 3.
In a 59-page decision, Judge Kathryn Kimball Mizelle, an appointee of former President Donald J. Trump, voided the mandate — which also applies to airports, train stations, and other transportation hubs — nationwide on several grounds, including ruling that the agency had exceeded its legal authority under the Public Health Services Act of 1944.
Because of the ruling, the masking order was not in effect for the time being, an administration official said on Monday evening, and the Transportation Security Administration would not enforce it.
The official said the administration was still reviewing the decision and assessing whether to appeal it, and that the C.D.C. still recommended that people wear continue to wear masks in enclosed public transportation settings.
It remained unclear whether any local transportation agencies or airlines would seek to keep their mandates in place. Earlier in the day, before the official said the T.S.A. would not enforce the mandate, a series of state and local transit agencies across the country suggested they would keep their mask mandates for now.
Still, governments and businesses across the nation have largely loosened precautions even as new known coronavirus cases are sharply rising again. Last week, the C.D.C. extended the mask rule until May 3, citing a desire to assess the potential severity of the Omicron subvariant known as BA.2, which recently became the dominant version among new U.S. cases. On Monday, the city of Philadelphia reinstated a mask mandate in response, becoming the first major city to do so.
There were signs the ruling could lead to some confusion. On Monday afternoon, Sara Nelson, the president of the Association of Flight Attendants, a union representing around 50,000 workers at 20 airlines, said in a statement that she was awaiting “more legal analysis on what this means” and that it would take a minimum of 24 to 48 hours to enact and communicate new procedures.
“We urge everyone to practice patience, remain calm, and to continue to follow crew member instructions,” she said. “And we remind passengers that it is legally required to follow crew member instructions, and that disruptive behavior has serious consequences as it puts everyone at risk.”
President Biden had called on the C.D.C. to issue a mask mandate for travelers shortly after his inauguration, and the agency did so on Feb. 2, 2021. It extended that mandate several times. In July 2021, the Health Freedom Defense Fund, a Wyoming-based advocacy group, filed a lawsuit challenging its legality.
The group could not be immediately reached for comment on Monday. But Judge Mizelle largely accepted its arguments, ruling that the agency had exceeded the authority Congress granted to it to prescribe public health measures like “sanitization,” saying that power was limited to cleaning property — not requiring people to take hygienic steps.
“If Congress intended this definition, the power bestowed on the C.D.C. would be breathtaking,” she wrote. “And it certainly would not be limited to modest measures of ‘sanitation’ like masks.”
If the government’s interpretation of the agency’s powers were accurate, she added, the C.D.C. could require businesses to install air filtration systems, mandate that people take vaccines, or even require “coughing into elbows and daily multivitamins.”
The ruling joins a tangle of litigation over various mandates attempting to curb the pandemic, most of which have centered on requirements, issued under various legal authorities, that different categories of people get vaccinated.
Legal challenges to those mandates have varied. For example, a Federal District Court judge in Texas had blocked an administration requirement that federal workers be vaccinated, but this month, an appeals court reversed that ruling.
In January, the Supreme Court blocked a Biden administration edict that large employers require workers to get vaccinated or submit to regular testing. But the Supreme Court has permitted military officials to take vaccination status into account when deciding where service members should be assigned or deployed — and on Monday, it allowed the Pentagon to take disciplinary action against a reservist who refused to get vaccinated.
Amtrak officials said shortly after the ruling was issued that the agency would keep its mask mandate in place, pending further guidance from the C.D.C. and T.S.A.
“As we have seen with the vaccine mandates, these court decisions are subject to review on appeal,” Jason Abrams, an Amtrak spokesman, said in a statement.
Many public transit agencies across the country also appeared to be keeping their mask mandates in place in the hours after the ruling. Those include the Metropolitan Transportation Authority in New York City; New Jersey Transit; the Metro and bus system in Washington, D.C.; the Massachusetts Bay Transportation Authority in Boston; the Southeastern Pennsylvania Transportation Authority in Philadelphia; and the Chicago Transit Authority.
President Trump appointed Judge Mizelle to the bench in November 2020, after he had lost re-election. A former clerk to Justice Clarence Thomas, she was 33 years old at the time, making her the youngest person Mr. Trump appointed to a life-tenured judgeship; the American Bar Association declared her not qualified because of her lack of experience, but Republican senators confirmed her in a party-line vote.
Lawrence Gostin, a professor of global health law at Georgetown University, said that the Biden administration would have to appeal the decision if it wanted the mandate to continue. He also defended the agency’s authority to issue the mask requirement.
“If there were ever an instance where the C.D.C. has authority to act, the classic case is to prevent the interstate transmission of a dangerous infectious disease,” he said.
Apart from the legal issues concerning the scope of the C.D.C.’s authority to protect public health, as a matter of policy, Judge Mizelle’s ruling was greeted by some in the airline industry as a relief.
David Neeleman, who has founded several airlines including JetBlue Airways and Breeze Airways, which started flying last year, said he welcomed the end of a mask mandate for passengers. Crew members at Breeze, where Mr. Neeleman is the chief executive, have been frustrated by having to police passengers, creating unnecessary tension in flight, he said.
“If the government can decide they can have the State of the Union address without masks, then we certainly should be able to let people have that choice on an airplane,” he said.
Last month, the executives of major airlines — including Delta, American Airlines, and United Airlines — had asked the Biden administration to let the mask mandate on planes and in airports to expire in a joint letter.
Judge Mizelle also faulted the agency for issuing the mandate under emergency procedures without delaying public comment about the proposal — rejecting the idea that there was no time for that since the pandemic was then already a year old.
“The C.D.C. issued the mandate in February 2021, almost two weeks after the president called for a mandate, 11 months after the president had declared Covid-19 a national emergency, and almost 13 months since the secretary of health and human services had declared a public health emergency,” she noted. “This history suggests that the C.D.C. itself did not find the passage of time particularly serious.”
In stressing that 11 months had passed between when “the president” had declared a national emergency and the agency imposed the mandate, Judge Mizelle did not address the fact that a different administration had just taken office.
As of Sunday, there was an average of more than 37,000 new cases a day, an increase of 39 percent from two weeks ago, according to a New York Times database.
Though the figure remains far lower than the peak of the winter surge driven by the Omicron variant, experts believe that new cases are increasingly undercounted with the rise of at-home testing. Many people who are vaccinated and have received booster shots have not experienced serious illness from contracting the Omicron variant. And because home tests have become so widely available and the results rarely reported, the number of cases recorded by federal and local officials in many states have been low estimates or undercounts.
Pulling back on the travel mask requirement at this moment was “very, very concerning,” Saskia Popescu, an infectious disease epidemiologist and assistant professor at George Mason University, said.
“We’re definitely starting to see a trend up in cases,” she said. “My concern is that we may see what happened in the U.K., where they drastically pulled back restrictions and saw a significant surge, and this will contribute to rising numbers.”
Reporting was contributed by Noah Weiland and Madeleine Ngo from Washington, and Ana Ley, Adeel Hassan, Niraj Chokshi Roni Caryn Rabin from New York.