When does parental obligation end?

Answer

Legally? When a mentally competent child turns 18 a parent has no legal obligation to the child. I have no idea if the child is mentally incompetent.

Morally? I guess that would be up the the parent and their relationship with the child.

I have a 20 year old Autistic son at home. Legally, I do not have to care for him but morally? I love him and do not want to see him homeless so he works and I handle his money so that he does not blow it all while I continue to teach him about the real world, bill and obligations so that one day he may be a productive citizen.

We make him pay rent which in turn I will give back to him when he moves out (even though he does not know that) and I make him purchase his personal products and clothing while I still prepare meals for the family so we do not make him purchase separate food unless he wishes to eat something else.