Originally Posted by PHXflier

You need to book a non-refundable hotel, and when you book you will see a note on the booking page whether it qualifies for the Delta AmEx credit. There is no minimum spend. If your hotel is less than the credit that you have for the year, you are able to use the remainder of the credit on other reservations until depleted. You get charged for the full amount, and the credit typically shows up on your account within a day or so.