Originally Posted by
sdsearch
It shouldn't count as a new account against 5/24, since you'll inherit the account history from your Premier card. It may or may not be a hard pull (because of the vastly different product lines, and/or just your personal status at Citi), you'll have ask about that when product changing.
The odds are good that you will get a new a/c number though, since Costco card runs off the Visa network, and most other Citi cards are on MC