Airlines are quickly expanding their refund and waiver policies to keep up with coronavirus developments. Most airlines are leaving March very flexible for travelers. Delta is standing out for offering the most flexibility.

Delta is waiving change fees for all travel that was due to depart in March, April and May. Tickets purchased from 1 March to 15 April will qualify. You'll need to cover the difference if your new fare is more expensive. Delta will issue an eCredit voucher for the difference if your replacement flight is less expensive. The airline is extending the travel window to December 31, 2020. If you need to cancel your flight due to coronavirus, your unused ticket will be converted to an eCredit within 24 hours of your originally scheduled travel. Delta will help you process your cancellation even if you do not manage to get in touch with customer service before your flight.

American Airlines will allow customers who purchased tickets before 1 March for travel through 30 April to rebook with no extra fees. You'll just need to complete your travel by 31 December or one year from your original issue date (whichever is earlier). American will be charging the difference if your new ticket is more expensive. However, it also looks like American will compensate you the difference if you book a cheaper replacement ticket.

United's general waiver isn't all that generous. United Airlines is allowing passengers to change plans for free on any flights scheduled through April 30. Date of ticket purchase and destination won't matter for this waiver. United will not give you a refund if the replacement flight you book is cheaper than your original flight. You'll also need to cover cost differences if your new ticket is more expensive. Fare-difference exceptions and full refunds apply if you were planning to travel to Italy, China, Hong Kong or South Korea.

Things are pretty much the same as usual at Southwest. Southwest's existing cancellation policy of no change fees is standing. All changes and cancellations for any travel dates will be free of fees. Passengers may need to pay fare differences when changing flights. All unused refundable tickets can be applied toward future flights or refunded within one year of the issue date.

Scott Dylan is a contributing writer at GET.com and has been to (almost) every country in North, Central and South America with nothing more than a backpack, a laptop and the desire to explore. He speaks Spanish fluently and has logged enough time in planes, trains, rideshares, buses, taxis and rickshaws to know how to rack up rewards and points to get anywhere his heart desires for pennies on the dollar. Email: scott.dylan@get.com.