The natural or adoptive parents, or the survivor of them, of a person who has been determined to be a person with developmental disabilities under regulations of the director of the department of behavioral healthcare, developmental disabilities and hospitals, may appoint at any time a parental successor for the person. The appointment shall be effective upon the death of the surviving parent and shall be for the period of the lifetime of that person with developmental disabilities.
R.I. Gen. Laws § 40.1-23-1