US-based airlines have canceled thousands of flights as the coronavirus pandemic spreads across the country. In the last week of March, the number of scheduled flights was down by 23 percent compared to the same week last year as more people are staying home and suspending planned trips.

The Department of Transportation (DOT) announced on April 3 that both US and foreign carriers must give customers refunds, not vouchers, for flights that were canceled by the airline or significantly delayed.

“Airlines have long provided such refunds, including during periods when air travel has been disrupted on a large scale, such as the aftermath of the September 11, 2001, attacks, Hurricane Katrina, and presidentially declared natural disasters,” the agency said. The enforcement notice comes amid increasing complaints from passengers who were denied refunds, and the DOT said airlines have a “long-standing obligation” to provide refunds, regardless of whether “flight disruptions are within or outside the carrier’s control.”

Since late January, US-based airlines have extended waivers and reduced flight capacity to various coronavirus hotspots in Asia and Europe. In March, several carriers announced cuts in service to domestic routes as they buckled down to reduce overhead costs. Most airlines have now expanded and waived change and cancellation ticket fees for both domestic and international flights as people reassess their travel plans. The DOT’s mandate will likely ensure that passengers will be able to get their money back if the airline experiences significant delays or cancellations that affect a passenger’s flight.

If you’re looking to reschedule a trip, be sure to read the terms and conditions of your waivers. However, most airlines are now allowing travelers who booked international and domestic flights to make changes without charge.

Airlines are changing their flight policies and schedules as the situation develops, so check the website of your carrier for more specific information. These are the latest airline updates as of April 3, including fee waivers, refunds, reduced flights, and the dates they currently extend to:

American Airlines will waive change fees for passengers who’ve bought a ticket prior to March 1 for travel through May 30, and for those who’ve booked a trip between March 1 and April 30 for future travel. Read all of American’s travel updates here.

Alaska Airlines will waive change and cancellation fees for tickets purchased on or before February 26 for travel through May 31, and for tickets purchased between February 27 and April 30. The policy applies to all of its fares, including its “saver fares,” which generally don’t allow changes or cancellations. Read more on Alaska’s travel advisories, updated in-flight service, and plane cleaning measures here.

Delta will waive change fees for all international and domestic flights through May and for travelers who purchased a ticket between March 1 and April 15. The airline has extended its flight credits for passengers, giving them up to two years to rebook travel. Read more on Delta’s travel updates here.

JetBlue will waive all change or cancellation fees for all flights through May 31. Passengers will be able to rebook their flights through October 24.

United will allow all passengers scheduled to travel through April 30 to change their flights without a fee. Customers who booked a trip between March 3 and April 30 and chose to cancel can also retain the value of the ticket without fee for travel up to a year from its original issue date.

According to the International Air Transport Association, demand for global air travel will decline for the first time since 2009, and airlines could lose up to $113 billion in revenue if Covid-19 continues — a forecast that suggests the outbreak could disrupt the industry as significantly as the Great Recession. Conferences and sporting events have been put on hold, and companies are taking precautions to limit employee travel.

Since January, airlines have been reducing service and offering waivers to travelers to mainland China, but with the virus’s ongoing spread, more and more passengers are hesitant to board a plane. British airlines have also canceled hundreds of flights throughout March.

As I previously reported, the travel industry is usually hit the hardest by pandemic threats. People are choosing not to travel, and politicians in cities and countries around the world are clamoring to secure their borders against the threat of a spreadable disease. During the 2003 SARS outbreak, which affected more than 8,000 people, stocks of US airlines dropped more than 30 percent (as did the economy overall), Barron’s reported.

Austin Horowitz, senior aviation management consultant at the global consulting firm ICF, previously told me that the financial effects of a major flight suspension “would not be much greater than people electing not to travel” since airlines are “already losing a significant number of passengers because people are not traveling voluntarily.”

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