how long does it take to get your ktn number after it is showing eligibility determined?
<answer> It takes 5 years to get your KTN number after it is showing eligibility determined. <context> If you do get approved for TSA Pre-Check, you can choose to receive your Known Traveler Number (KTN) either through the mail or online. When booking flights from airports that support Pre-Check, be sure to do so with an airline that TSA Pre-Check covers, and be sure to enter in your KTN. Your TSA Pre-Check eligibility is valid for 5 years, after which you will have to re-apply.