If you have an IEP or a diagnosis that entitles you to accommodations, and you are considering attending an Ontario College or University, the following website has specific information about the accessibility services available at all of the main colleges and universities in Ontario.
https://www.transitionresourceguide.ca/
Once you accept an offer, make an appointment (in the spring) with your institution’s Accessibility office, and take all of your documentation with you (this would include your IEP if you have one, any psychological testing reports that you have, and any applicable doctor’s letters). They will guide you about how their department handles accommodations, what you need to do to access them, and whether they require any additional information or testing.
If they do require further testing, and you are also eligible for OSAP, you might be eligible to have some of your testing paid for by OSAP. The accessibility office will direct you as to how to apply. It is not advised that you go and get tested before you have this meeting, because different institutions may have different requirements, and they usually give you a period of time in which to meet their requirements.
Another thing to consider is that if you have a diagnosis that makes it easier for you to work in a quiet setting, you may find that a private room in residence is best for you. Since many institutions do not normally allow first year students to have single rooms, you can get a letter from your doctor stating that you require a private room because of your need for a quiet setting.
You do not tell them during the application process that you have an IEP.