Originally Posted by Randyk47

Bottom line up front, you do not need your PreCheck KTN. Under Global Entry you get PreCheck as an added benefit and you use your GE PassID number in your airline profiles.

A couple of points though from your post. PreCheck is actually only eight years old. Secondly, a lot of people have been getting PreCheck from the airlines as part of an airline auto-inclusion program that has in the past been extended to frequent flyers or passengers who book first/business class tickets. That has tailed off a bit and while it still happens TSA supposedly wants to do away with the practice. People often mistakenly think the airline “enrolled” them in PreCheck but they haven’t and the passenger is not officially in PreCheck. To the best of my knowledge there has never been “auto-enrollment”. A quick check in your airline profile should tell you if you actually were enrolled as your KTN is part of your profile.