Can you add TSA PreCheck after booking?

Related questions

1. How do I find out when my TSA PreCheck expires?
2. How do you renew PreCheck?
3. Do toddlers need global entry?
4. How do I know if my TSA Precheck has expired?
5. Do I need to renew TSA if I have Global Entry?
6. Does Canada accept US Global Entry?
7. Can I bring my child through TSA Precheck?
8. Do I need my Global entry card?
9. Does clear Get You TSA Pre?
10. How do I know if I have a known traveler number?

Tags

1. #existing
2. #airlines
3. #reservation
4. #other
5. #changes
6. #phone
7. #provides
8. #reservations
9. #managing
10. #online
11. #allow
12. #members
13. #assignments
14. #actually
15. #would
16. #while
17. #precheck
18. #global
19. #entry