Originally Posted by ryan182

I've never had it on a domestic flight either, but also I've had pre-check since it was a pilot program and have assumed that having a KTN probably significantly lowers your odds of SSSS on domestic flights but I don't know that it prevents you from getting it. The one situation I've had that seems to trigger SSSS regularly is one-way international flights to the US from an international gateway, though that just gets you the extra treatment at the gate and doesn't effect you clearing security unless I suppose you're at an airport that does screening at each gate.