Medicaid question

Hi all. I am trying to figure out how medicaid works if you adopt a child from out of your home state. It's my understanding that the custody state (state A) will have the adoptive state (state B) issue a card and administer the medicaid part of it. The big question, assuming that I'm right about the above, is does the medicaid only cover what services the child would have been eligible for in state A, or does the administering state B cover the child in the manner that they cover their own dependent children. There seems to be a really wide range of services covered from state to state, and getting a clear answer is tough. Thanks,Sarah