What are the main factors that determine the Delta upgrade order?

The Delta upgrade order is the ranking of passengers who are eligible for an upgrade to a higher class of service on Delta flights. The upgrade order is based on several factors, such as the passenger’s Medallion status, fare class, Delta SkyMiles Reserve American Express Card membership, Delta corporate travel affiliation, and time of request. The higher the Medallion status and the fare class, the higher the priority for an upgrade. Delta SkyMiles Reserve Card members and Delta corporate travelers also get an advantage over other passengers in the same Medallion tier and fare class. The time of request is the last factor that breaks the tie between passengers with the same priority level. The earlier the request is made, the higher the chance of getting an upgrade. The Delta upgrade order is designed to reward the most loyal and valuable customers of Delta with a better travel experience.