I dont think you can product change to a different rewards program. You could upgrade it to another Delta branded card.
If the blue Sky is the plain Vanilla Blue card then it may be possible. They are supposed to be phasing this card out according to DOC articles.
Hop on chat with Amex and ask .
It’s not possible to change rewards program but if the card you have earns MR points it may be possible to do a PC to another MR earning revolver
Hop on chat with Amex and ask .
It’s not possible to change rewards program but if the card you have earns MR points it may be possible to do a PC to another MR earning revolver
