Airlines are notoriously strict when it comes to canceling or refunding plane tickets. Most charge passengers a fee of $150 to $200 to change an itinerary, and tickets are typically non-refundable, so it’s impossible to get all of your money back if you decide not to take the trip.

But the emergence of Zika has changed all of that. The Centers for Disease Control (CDC) believes that the virus causes birth defects in pregnant women, and can be sexually transmitted from partner to partner. The CDC has advised certain groups to avoid travel to areas with known cases of Zika, forcing airlines to loosen their policies to accommodate a growing number of travelers rethinking their vacation plans.

The CDC reports that Zika cases have been found in 55 countries and territories around the world. This week, the CDC shocked Americans when it warned pregnant woman against traveling to parts of Miami where it says mosquitoes are spreading Zika. So far, Florida health officials have identified 15 Zika cases which they believe have been spread locally, and they expect there might be more.

Zika travel warnings have been steadily growing since February, and each major US airline has updated their policies to deal with the rise in travelers looking for refunds. Most are willing to refund the flight completely, but each airline has their own cut-off date and rule about travel companions. Here’s a rundown of how each airline is handling Zika-related refunds.

Alaska Airlines

The following statement is applicable for travel to and from Fort Lauderdale (FLL), Orlando (MCO) and Tampa (TPA):

“We will waive the change fees if the new travel is booked and completed on or before June 13, 2017. You may also cancel your flight and request a refund if you choose not to travel at all. Tickets must be exchanged or refunded on or before August 16, 2016.”

American Airlines

“If you’re pregnant and traveling to a destination in Latin America or the Caribbean affected by the Zika virus, you and your travel companions can request a refund for tickets purchased on or before March 31, 2016. Just provide a doctor’s note confirming your pregnancy when you request a refund.”

Delta

Customers may qualify for a change to alternate destinations, travel dates or a refund. Customers may make fee-waived changes to future reservations/tickets if tickets were issued on or before March 1, 2016. If you are a Delta Vacations customer please call 1-800-800-1504.

JetBlue

Original travel must have been booked on or before August 1, 2016 in order for passengers to be eligible for a refund. If you are traveling on a Getaways package, a full refund is not always available and hotel penalties may apply. You can contact JetBlue by phone to request a change or refund.

United Airlines

“Customers who are advised to avoid the affected regions based on CDC guidance may change their destination or travel date without a change fee or may choose to receive a refund if their tickets were issued on or before February 29, 2016. The new travel date must be within the validity of the ticket. Additional charges may apply if there is a difference in fare for the new itinerary.”

United says this policy also applies to companions of pregnant women or people who were advised to avoid travel to Zika-infected areas.

Southwest Airlines

“As always, our customers can change their travel itineraries without a change fee and our non-refundable fares can be applied toward future travel without penalty as long as your reservation is cancelled 10 minutes prior to the scheduled departure of your flight.”

Spirit Airlines

“Customers planning to travel to a country that has been impacted by the Zika virus may contact us here with questions about changes to their itinerary.”

Brittany Jones-Cooper is a writer for Yahoo Finance.

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