Adding TSA PreCheck to your Delta reservation is a straightforward process that can save you time at the airport. First, ensure you have a valid Known Traveler Number (KTN) from your TSA PreCheck membership. Then, log in to your Delta SkyMiles account on Delta’s website or mobile app. Navigate to the “My Profile” section and select “Personal Details.” Here, you’ll find a field to enter your KTN. Input your number and save the changes. If you’ve already booked your flight, you can still add your KTN. Go to the “My Trips” section, select your upcoming flight, and choose “Add Secure Flight Info.” Enter your KTN in the designated field and save the updates. Your TSA PreCheck status should now be linked to your Delta reservation, allowing you to use the expedited security lanes at participating airports. Always verify your boarding pass for the TSA PreCheck indicator before heading to the airport.