Delta SkyMiles never expire as long as the account is open and in good standing, but you should frequently use your SkyMiles because Delta frequently devalues their points without notice.
However, Delta reserved the right to close your account and delete your SkyMiles if:
- Fraudulent activity occurs.
- A Member requests an account closure.
- A Member is deceased.
- A Member does not respond to repeated communication attempts regarding the status of his/her account.
- A Member resides in or relocates to a country where membership is prohibited under applicable law.
- A Member violates the terms of this Membership Guide and Program Rules.
Comparison of U.S. Airlines' Policies
Below are the mileage expiration policies for every major U.S. airline.