If your child is dyslexic, your child does not necessarily have to be on an IEP. They may do fine with a 504.
IEP stands for Individual Education Plan. When a child is receiving special education services they have to have an IEP. A special needs student will be working on goals that help them keep up with their peers. For example, a student who is blind will have an IEP goal to learn to read braille so they can read the same material as the other students in their class.
A 504 is a list of accommodations that a student needs to keep up with their peers. For example, a child with dyslexia would be allowed to record their papers because they are unable to express their full knowledge of a subject because they struggle to write fluently. It doesn’t get them out of the work. It just means they might do their work differently.
Many schools are not yet providing intervention for Dyslexia. Some will, however, set up a 504 plan.