Delta doesn’t have a blanket policy on changing or canceling your flight—it can vary based on the type of ticket you’ve purchased:

As per Delta Cancellation Policy, If you bought a refundable ticket, Delta allows certain changes and cancellations without penalty up to 24 hours after you purchase your ticket, as long as your flight is at least seven days away. The change fee would then be waived for any subsequent changes or cancellations.

If the ticket is non-refundable but you’ve bought travel insurance or the Ticket Protection Plan through Delta, some changes are allowed for a fee (usually $200) and may also require you to pay any difference in fare between your old and new flights.

If none of the above applies, you’re usually out of luck since no changes are allowed with a nonrefundable ticket. You can apply for an exception, however, if there has been a death in the family or if you or someone traveling with you has been seriously injured; this will require proof of death or injury and an explanation of how it affects your ability to travel according to the original plans.