Almost all parents have a will. They agonized over choosing a guardian and figured out how to split there assets. If the parents have a special needs child they most likely chose someone based on their knowledge of the child's disability. I know we did. There is one thing that most parents don't think about, does the child's guardian know every doctor, social worker etc?
Think for a moment of all your child's doctors, therapies, and conditions. This probably took you a few minutes. Now add on medications, phone numbers, addresses. You are probably thinking how am I suppose to know all that offhand. Well, now put yourself in the child's guardian shoes. They have to try to figure out. That's why it's important to keep files (This is important for other reasons, but that's another post)!
I always suggest making two files one for home and one to give to the guardian. These files should contain doctors names, addresses, phone numbers, and what the child sees them for. You should add on all medications, therapy days, times, and the therapist phone numbers. A list of everyone of the child's conditions. If the child gets SSI, medicaid, or any other services add on all the social workers names, phone numbers, and what it is they do.
A simple spiral notebook can even serve as a file. Just make sure whatever you use can be updated and added to. If anything ever happens to you the guardian will be able to go down the list and be able to find out next appointments, any paperwork that will have to be done, etc. You have no idea how much easier this will be and the child won't miss anything because no one knew about it.