I don't know anything about your state, but I can tell you what I know exists out there-

I'll preface this with I live in NY, but every state has some kind of governing agency that oversees fields like mental health (here it is "Office of Mental Health" or OMH) and services for the ID/DD population (In NY it is the Office of People With Developmental Disabilities ie OPWDD).

Within OPWDD there is a myriad of services ranging from Service Coordination (Holla), to Day Habilitation, Supported Employment (SEMP), Community Habilitation (where a worker is assigned to an individual and helps teach them lifeskills outside the classroom/access/integrate into their communities), Respite Services (essentially, down the bare bones, this is supervision when the primary caretaker needs a break and can be in the community or at a Respite Center), Residential Habilitation (a group home) and I could keep going.

Whatever your state calls it's Service Coordinators (Case Managers, Care Coordinators etc) you need to find a way to get hooked up with one. This person will be your best friend and your guide through all of the services that are available to your SS. They will know how to apply for, obtain and maintain these things on Federal (SSA), State, County (Medicaid) and local levels. This is what I do for a living, so I know it's out there and it never ceases to amaze me how long parents go without ever being told that these services exist.

They can help you outline SS's goals, your goals for SS and develop a how-to plan to get you there both short and long term.

I would ask the therapist if they know anything about any of that so they can point you in the right direction.

Theses questions can not be answer with out spending time with your SS.
You must know what’s he is capable of doing. Can he show up on time. Can he focus on the job given to him
Should be able to do some type of chores

Even if this were your bio child in an intact home I would encourage you to use all resources available to let this child become as independent as possible for his benefit most of all. I have many friends with disabled children - it is SO IMPORTANT for these children to be as independent as possible for their benefit.

I've seen extremely disabled young adults be so happy with their independent life. I've also seen disabled children who were sheltered at home until the last parent died who became inconsolable. Even if siblings were more than willing to take over care the extremely sheltered person could not accept change.

No input other than a share.

MY super BFF had a son the same age as your husbands ss18.He was difficult in primary school, not only was there intermittent mild aggression, also, blurting things out that WE think but never ever would say in polite company. He was mostly a polite funny kid. At around 10 years old he was diagnosed with Asperger's. He did graduate HS and my BFF homeschooled him when her and her dh realized the school could not handled him. It was not for a lack of trying on the schools part because they did. Mom and dad believed he was best educated AND more comfortable at home. The teen went part time at local community college then decided he would drop out. One day going to college the next day a drop out.

Anyway HE (the son) was a huge challenge at a drop of a dime. His age, his size as a young man made things very difficult for mom and dad. Having a child with Asperger's is hard NOW have an adult with Asperger's.

Your DH will no longer be able to access any medical information about his son now that he is 18. What challenges will that bring dh? A LOT.

Who takes care of SS18 social security checks each month? What challenges will that pose you dh now?

Are you and DH ready and I mean, really ready to meet the demands of SS18. What about when he becomes physically aggressive.?

What plans has dh made to secure the future of his son? Where will son go IF DH passes away unexpectedly?

There was a documentary titled "Best Boy". Look it up.

I encourage you to watch it sometime. I am not saying your husbands ss18 is like Philly.

Some times things are bigger than we are. Some times we cant see the forest thru the trees.

Sometimes we don't want to see what is best for someone else because we think we know what is best for them.

Best wishes and by the way---Hopefully the Grandparents can continue to enjoy the rest of their days. VERY difficult to raise a grandchild.

I live with a high functioning AS Stepson now 18 (still at school). I have been around him since he was 8 years old. He was very Autistic with a lot of difficult behaviours etc. From the way BM and her family treated him it was aparent that he could do better. DH had tried to improve his behaviour and teach him some skills but BM undermined everything he tried. Her attitude was 'but he's autistic, he can't do anything'.

BM then left DH and of course left both her children with him. She graciously had them eowe. Later, I come along and having worked in education and had training in behavioural issues and therapy plus experience with autism, I could see that a large part of the problems he displayed were behavioral and not in fact due to AS (although compounded by AS). We set about working on these problems, BM of course, set about undoing everything we did. As he spent most of his time with us it eventually began to work. BM did not like this but was too self centered and lazy to do anything herself.

OP - what I would say to you is that grandma has had him for a long time right? She would be the one that I would ask these questions. His school too. A good talk with them should give you a lot of information. Some people seem to have the idea that people on the AS spectrum cannot learn or improve their abilities with regard to social situations, getting along with others etc. How to behave. They can, but it's very slow and needs constant repetition and a LOT of hard work. If you do not keep up with reminders and guidance they immediately begin to fall back.

Do you really want to take on all this responsibility? As a non bio parent it is really hard. I have now mostly disengaged unless his behaviour directly affects me and just give support and some guidance to my DH who is a hero with all the rubbish that boy and his estranged mother throw at him.

It sounds to me as if your SS is likely to be permanently dependant. In the UK only 16% of people on the AS spectrum have a job. Think about this. Do you really want this?