the question re whether or not your ds needs a 504 or an IEP depends on whether or not he needs individualized instruction (an IEP) or accommodations to allow him to fully participate in the classroom and to be able to demonstrate his knowledge (504). If a student has an IEP and needs accommodations, they are typically included in the IEP rather than having a 504 plan while the IEP is in place.
One other thing to consider - a 504 plan is quicker and easier to put together. An IEP will require eligibility testing by the school in addition to the documentation you already have. A 504 plan can most likely be written from the private eval report that you already have. On the other hand, IEPs come with more legal protections and requirements for the school to follow the paperwork whereas 504s seem to have less safeguards built in. All that said, the deciding factor re pursuing an IEP vs 504 should always be - does my student need an individualized education plan, or will he/she be able to fully access their education with accommodations through a 504.
Fabulous summary!
Parents need to have this high-level understanding, and ALSO have
resources which they can consult for detail, refer to as experts by name, and quote in meetings, lending authority and strength to the parent's position and presentation, if needed.
