For domestic and international flights leaving from the United States, Delta Airlines no longer charges customers to change flights. Only if your new flight ticket is more expensive will you be required to pay the fee difference. The charge waiver does not, however, apply to Basic Economy tickets, which are non-refundable. In some circumstances, you may be able to modify your flight (date, time, and/or destination) or request a refund in the form of an eCredit under Delta Airlines' flight adjustment policy.
Below is a snapshot of Delta Airlines change flight policy:
Fees for Delta Airlines Flight Changes
Depending on your itinerary, the cost to modify a flight might range from USD 200 to USD 500 if it is not covered by a change fee waiver. Remember that Basic Economy tickets cannot be changed or rebooked unless they are covered by a travel waiver or you cancel within 24 hours and rebook to accommodate your changing preferences.
Delta Airlines Basic Economy Ticket Change Fee Waiver
For tickets purchased in Basic Economy, Delta Airlines has waived the change charge (included). Despite the fact that Basic Economy tickets are typically non-changeable, during this time you are able to make adjustments to any Basic Economy flight ticket without paying a flight change charge.