Question about retroactive feat qualification

[LookingForABentoBox]

If I eat a tome at n level, can I go back and switch a feat from a level before n that only meets the minimum stat requirement by eating the tome? Case in point, if I get a +3 int tome at level 20, and base int was 10, can I switch the level 18 feat to combat expertise?

[dkyle]

Yes, that works. I've personally done something similar: I started Corlonius with 15 Dex, which meant his dex didn't qualify him for improved two-weapon fighting at level 6. I took some other feat instead, then ate a +2 tome at level 7, and swapped it out for improved TWF.