In New York, I received services for 3 of my 5 children when they were under the age of 3 by contacting my local Department of Health, which administers the Early Intervention Program. My difficult child received speech therapy, my now 5 year old got speech and PT and the 2 1/2 year old received 6 months of PT to help him learn to walk (he has a congenital hip deformity which does not require surgery, but which did require that he be trained to walk as it did not come naturally to him. Now you could never tell that he wasn't always running and climbing!)
Your child is evaluated for free under this program (which I think is federally mandated, but I'm not sure). ALL evaluations include a psychiatric and social component and then additional sections are added as warranted. For instance, difficult child (whom we call Rocket Ryan!) did not get a PT evaluation as his gross motor skills were great, he did have an Occupational Therapist (OT) evaluation and actually got Occupational Therapist (OT) for a few months. He had his evaluation during potty training and because we had just moved, we had delayed training him, he was past 3 and they found him delayed. He was fully trained within 2 weeks of the evaluation, but he got the Occupational Therapist (OT) for a while. The now 5 year old had a bit of PT because the sitter had kept him cooped up all the time and he was a slow walker, but he did not need Occupational Therapist (OT). He did have a SEIT in nursery school, which sounds like it might be a good idea for your Ryan. A SEIT is a Special Education teacher who stays with your child at preschool and helps them to function. Avery had it twice a week for an hour. The joke was that he didn't need it and she spent most of her time working with another little boy whose parents were in total denial of his situation and who needed her more than my son did. To show how subjective the evaluations can be, Avery had his at about 11 AM on March 11th; at 11 PM, I gave birth to David. Ave had wanted to be with me during the evaluation, but I had husband stay with him because I could not lift him (he was 2 1/2 at the time). I stayed with difficult child, who was also being tested at the same time. They found Avery to have severe separation anxiety and a social phobia! In reality, all Avery ever had was a speech delay. I could have used the SEIT for Ryan but because he was with me during the evaluation, they did not note the same things.
My point is that there are services for the under 3 set, but since your son will be 3 so soon, your best bet is to start the process now with a testing agency that your school district will also accept. The school must give you a list. The services for 3 to 5 year olds is called (here at least) Committee for pre-school special education. In my district and most that I know of, you must go to the local office with proof of residency and of your child's age (proof of US citizenship is NOT required, to my knowledge) and fill out a request for services form. You are then given a list of places that test (you do not pay for the testing) and you set up the appointments. When all are done, including forms from your pediatrician and hearing evaluations if speech is a concern, a meeting is scheduled between the providers, the SD and you. It is usually easier to get services at this level, because the providers get paid by the SD per kid, so they are more willing to recommend services. By school age, the people who do the recommending are employed by the people who do the paying, so there is more of a conflict there.
In any event, don't let the school district tell you you need to wait until he is 3 to start with this. You can start with EI and then age him out to pre-school, but only if you use a facility on the acceptable lists of both. You are lucky; I never heard of early intervention or pre-school committee until my oldest was already in kindergarten!
Good luck ! Michele