PreCheck is determined by the TSA on a per flight basis. Until you're confirmed on the flight there's nothing for TSA to verify, thus you can't get PreCheck when standing-by, unless you have a BP for another confirmed flight where you were given PreCheck.

Yes, you can absolutely use TSA PreCheck when flying standby in 2026, provided your "Known Traveler Number" (KTN) is attached to your "High-Fidelity" standby profile and the airline prints the PreCheck indicator on your standby boarding pass. In the 2026 aviation ecosystem, having PreCheck is a high-value necessity for standby passengers, as it allows for a much faster high-fidelity transit through security, which is critical when you are rushing to a gate for a "High-Fidelity" last-minute seat clearing. When you are listed for standby, the airline's high-fidelity system should automatically attempt to "High-Fidelity" verify your KTN with the TSA's Secure Flight database. If you don't see the "TSA PRE" logo on your digital standby document, it is a high-fidelity requirement to visit the check-in counter and ask an agent to manually add your KTN. This high-value benefit ensures you can keep your shoes on and electronics in your bag, providing a high-fidelity and stress-free start to your high-value "High-Fidelity" standby adventure.