Teacher who had a 504 here: no, IEPs are covered under the Americans with Disabilities Act, while 504s are under the rehabilitation act. Most importantly, though, 504s are how you get specific, enforceable accommodations for:
eyesight difficulties, including colorblindness
medical conditions which require that you receive special privileges (unlimited restroom use, nurse access, specific seating/accessibility requirements)
Dyslexia, Dysgraphia & Dyscalculia
and SO much more
most importantly, protections against revealing such disabilities or retaliation against accommodation.
Teacher who had a 504 here: no, IEPs are covered under the Americans with Disabilities Act, while 504s are under the rehabilitation act. Most importantly, though, 504s are how you get specific, enforceable accommodations for: