Global Entry Members are eligible to participate in TSA PreCheck. For Global Entry member, you have a membership number (PASS ID) and please enter the PASS ID in the “Known Traveler Number” field when booking reservations, or enter it into your frequent flyer profile with the airline. The membership number enables Transportation Security Administration’s (TSA) secure flight system to verify that you are a legitimate Trusted Traveler.
Both my wife and I have Global Entry, when we got our boarding pass, 50% of the time we did not have TSA PreCheck shown on the boarding pass. In the past, we just let it be and went through the regular security line. Until our recent trip to Las Vegas, we called the Southwest Airlines Customer Services and questioned why our TSA PreCheck was not shown on the boarding pass, the representative was trying to re-issue a new one, but it still did not solve the problem, He ensured me that the PASS IDs were in our profile. He suggested us to go to the airport counter to get a new boarding pass. Yes, the airport counter was able to provide us with a boarding pass with TSA PreCheck and she explained to us that 50% of the chance the TSA PreCheck will not be shown and she did not know why either. If you are facing the same problem, I guess the solution is to get a new re-issue boarding pass at airport. Although you are wasting sometime at airport counter, you are still saving a lot of time at the security checkpoint because it is a shorter line and you do not need to take out your laptop, ipad, iPhone, and take off your shoes, belt, and watch.