Just who is it that told you that? Not the name, but the position, title, department?
I ask because it appears that the person is clueless.
Power of Attorney and Guardianship are two entirely different things and are worlds apart. Power of Attorney is a piece of paper that a person signs that allows somebody else to do stuff and sign stuff on his behalf. Guardianship is something you have to be granted by a court and involves being completely in charge of another person's life.
I suggest that you recontact that person and ask to read something in print about qualifying your son.
Or call:
Kaiser Permanente Medicaid Assistance Center at
1-800-557-45151-800-557-4515 (toll free)
8 a.m. to 5 p.m., Monday through Friday.