Originally Posted by
happydad100
Good question. From the Delta website:
"Complimentary Upgrades are not permitted to Delta Premium Select or Delta One® flights outside of the U.S. 50."
Here is more information:
https://www.delta.com/us/en/skymiles...llion-upgrades
Basically, the only way to upgrade to Premium Select or Delta One is to pay with cash (you may see an upgrade offer on your trip) or repurchase your ticket.
Unless you are become a Diamond Medallion and use Global Upgrades as one of your Choice Benefits:
https://www.delta.com/content/www/en...-benefits.html
You can sometimes upgrade to Delta One from certain fare classes (Premium Select and some Economy fare classes) with a Mileage Upgrade Award. I don’t know if you can upgrade to PS with a MUA; I’ve only done if from PS to D1.