Our DS is almost 4 and we tried EI in both Texas and CA. In my opinion, the services you can get through EI vary widely depending on where you are!
In TX we had a very bad experience, they offered us very little and the services they did offer were very spotty.
In CA the system was much better and we encountered a number of great therapists. HOWEVER, we also found that it was clearly a "system" that had a hard time accommodating non-standard issues. For example, our county is GREAT for kids on the spectrum, but for other delays it didn't have the right tools to help us deal with our DS's unique issues (namely a severe language disorder).
We ended up pulling DS from the special ed preschool because it was not good for him - great for some kids, but not for what our DS needed (which was some sensory therapy and lots of help with speech and social pragmatics).
My point being that I would be aware and educate yourself about the kinds of therapies and approaches available that could impact you little one, and then pay attention to OUTCOMES! Yes, listen to the EI folks and be open to what they say, but also pay attention to how your specific child is responding to specific interventions and then fine tune - keep what works and say no thank you to what doesn't. I know its hard, but trust your gut and watch your little one and you can't go wrong!
My other advice is that I had to become a very vocal advocate for our DS. Obviously don't be mean, but you might need to be aggressive sometimes. I found that being the squeaky wheel really helped us get the things we wanted for DS.
In the end, even though the EI people were well meaning and dedicated, we ended up going with private therapists (some of which were covered by insurance and some that weren't, ugh) because we were able to really tailor things to our DS's needs.
I'd say the fact that you're already thinking about this means you will be great at navigating EI!
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