Wherever you move, apply for DD-Medicaid waivers immediately. States govern these programs, so evaluating what services the two states provide can be helpful (but challenging). Here is an overview in VA: https://www.youtube.com/watch?v=22BrSd9BtpM

I lived in Prince George’s County, MD and I moved to Fairfax, VA for better services, and to be close to my family. In MD your best bet is Montgomery County or Howard County. I believe in VA parents’ insurance companies are required to cover ASD kids for their whole lives. In MD I think it is until they are 18yo. Might not be an issue if they qualify for medicaid.