‘I am pursuing adult adoption. I am choosing to be legally adopted by my step-father. My biological father is still alive. I have four half-siblings from my biological father. Will I still be legally related to my half-siblings after I am adopted by my step-father? If so, what kind of legal relationship would they still have with me? Would they still have any legal authority for medical decision making or inheritance rights? Thanks.’
This is a very complicated question in a complicated area of law. You really need to speak with an attorney in your own state who specializes in adoption.