On Monday, Judge Kathryn Kimball Mizelle, who was appointed by former President Donald Trump, ruled that the federal mask mandate on airplanes, trains and buses, “exceeded” the U.S. Centers for Disease Control and Prevention’s (CDC) authority.

The ruling comes just a few days after the CDC announced that it was extending its mask mandate on planes and other mass transportation methods due to the spread of the COVID-19 Omicron variant.

Now that the federal mask mandate has been struck down, it will fall to individual transportation providers to determine if they will continue to enforce mask-wearing on their own. On Monday, Newsweek reached out to several major U.S. carriers to determine their position on masks in the wake of Mizelle’s ruling. The TSA said in a statement on Monday that it “will no longer enforce its Security Directives and Emergency Amendment requiring mask use on public transportation and transportation hubs.”

“TSA will also rescind the new Security Directives that were scheduled to take effect tomorrow. CDC continues to recommend that people wear masks in indoor public transportation settings at this time,” the statement added.

Following the statement issued by the TSA, Delta Airlines removed mask requirements. “Effective immediately, masks are optional for all airport employees, crew members and customers inside U.S. airports and on board all aircraft domestically, as well as on most international flights,” the airline said in a statement.

United Airlines also dropped its mask requirements. “Effective immediately, masks are no longer required at United on domestic flights, select international flights (dependent upon the arrival country’s mask requirements) or at U.S. airports,” United said in a statement.

A spokesperson for Allegiant Airlines told Newsweek that its “mask policy remains unchanged at this time.”

“This is a dynamic situation that we are closely monitoring, as we’re anticipating further clarification on the implementation of the judge’s order,” the Allegiant spokesperson said.

In a statement sent to Newsweek, a spokesperson for Jet Blue said, “In line with Monday’s federal court ruling and the Transportation Security Administration’s guidance, mask-wearing will now be optional on JetBlue. While no longer required, customers and crewmembers are welcome to continue wearing masks in our terminals and on board our aircraft.”

Alaska Airlines and Southwest Airlines both directed Newsweek to statements on their websites that said masks are no longer required on flights on both carriers. American Airlines also issued a similar statement, saying the mask mandate will not be enforced.

A spokesperson for Frontier Airlines also confirmed to Newsweek that they will no longer enforce a mask mandate on their flights.

“Effective immediately, Frontier Airlines customers, crew members and other team members are no longer required to wear masks onboard Frontier aircraft,” the spokesperson said.

Newsweek also reached out to Spirit Airlines for comment.

In addition to airlines, the federal mask mandate also applied to trains and buses in the U.S.

Tim Minton, communications director for New York’s Metropolitan Transportation Authority (MTA), told Newsweek that masks will still be required on the MTA. “The mask requirement on public transit in NY remains in effect for now pursuant to a March 2, 2022 determination by the New York State Department of Health,” Minton said.

In a statement sent to Newsweek, a spokesperson for Amtrak said, “While Amtrak passengers and employees are no longer required to wear masks while on board trains or in stations, masks are welcome and remain an important preventive measure against COVID-19. Anyone needing or choosing to wear one is encouraged to do so.”

Both Uber and Lyft also announced that masks were no longer required for riders in the U.S.

A spokesperson for the Denver International Airport also told Newsweek that until the airport receives “further guidance from the federal government, DEN remains in compliance with the current mandate.”

“The safety and security of passengers and employees is the highest priority for the Chicago Department of Aviation (CDA). The CDA will continue to follow, observe and enforce all current and future guidance by federal, state and local health and security authorities,” the Chicago Department of Aviation said in a statement sent to Newsweek in response to a question about policies at Chicago O’Hare International Airport.

The Dallas Fort Worth International Airport also issued a statement following the ruling saying that it will no longer enforce a mask mandate.

Newsweek reached out to several other major airports in the U.S. for comment, including John F. Kennedy Airport in New York; Los Angeles International Airport; and Hartsfield-Jackson Atlanta International Airport.

The Association of Flight Attendants-CWA said in a statement that it was still trying to determine what the ruling would mean for its members.

“We will soon have more legal analysis on what this means and what next steps may be taken in court by the government,” the association’s statement said. “We urge focus on clear communication so that Flight Attendants and other frontline workers are not subject to more violence created by uncertainty and confusion…Immediately, we urge calm and consistency in the airports and on planes. The last thing we need for workers on the frontlines or passengers traveling today is confusion and chaos. Traveling can be stressful enough and safety comes first with respect for everyone utilizing collective modes of transportation.”

Christopher Anderson, a professor of operations, technology and information management at Cornell University said he also hoped that travelers continued to respect carriers’ policies.

“Many travelers are looking forward to the removal of mask mandates – especially for some of those longer flights,” Anderson said. “The recent federal judge’s decision, while raising the hopes of many, conflicts with CDC guidelines and, as we have all experienced – inconsistency is the worst possible outcome when facing mandates and restrictions.”

“Mandate inconsistencies create very difficult situations for airlines and their employees,” Anderson continued. “My hope is that travelers respect the decisions of others along with the policies of service providers. Airlines will most likely need to adjust the language they use when communicating with travelers, and I expect we will soon see differing levels of mask use at airports and other forms of public transportation.”

Newsweek also reached out to the Transport Workers Union Local 556 for comment on the ruling.

Florida Governor Ron DeSantis praised the judge’s decision to strike down the mask mandate on airplanes.

“Great to see a federal judge in Florida follow the law and reject the Biden transportation mask mandate,” DeSantis wrote on Twitter. “Both airline employees and passengers deserve to have this misery end.”

On April 13, the CDC issued a statement announcing that it was extending its mask mandate on airplanes and other mass transportation methods.

“The CDC Mask Order remains in effect while CDC assesses the potential impact of the rise of cases on severe disease, including hospitalizations and deaths, and healthcare system capacity. TSA will extend the security directive and emergency amendment for 15 days, through May 3, 2022,” the CDC said in a statement on April 13.

However, following the ruling on Monday, the CDC issued a statement saying, “As a result of a court order, effective immediately and as of April 18, 2022, CDC’s January 29, 2021 Order requiring masks on public transportation conveyances and at transportation hubs is no longer in effect. Therefore, CDC will not enforce the Order.”

Update 4/19/22, 10:59 a.m. ET: This story has been updated with additional information and background.