(1) A child under 17 years of age, provision for whose support and education has been made under regulations of the department, may be admitted to the Michigan children's institute by commitment to the department. All children committed to the Michigan children's institute shall be considered committed to the department and shall be subject to review by the juvenile division of the probate court under chapter XIIA of the probate code of 1939, 1939 PA 288, MCL 712A.1 to 712A.32. The superintendent of the institute shall represent the state as guardian of each child committed beginning with the day the child is admitted and continuing until the child is 19, unless the superintendent or the department discharges the child sooner as provided in section 8 or 9 or if the child is at least 18 years of age but less than 21 years of age and is participating in extended foster care services as described in section 11 of the young adult voluntary foster care act. Wherever commitment to the Michigan children's institute is mentioned in any law of this state, it shall be construed to mean commitment to the department. A child may be committed to the department by either of the following:

    (a) By the juvenile division of the probate court, if the child is within the court's jurisdiction under section 2(b) of chapter XIIA of the probate code of 1939, 1939 PA 288, MCL 712A.2.

    (b) By the probate court, if the child is a ward of the court and the court has denied an order of adoption for the child.

    (c) By observation order. If a child has been decreed to be a ward of the probate court or the juvenile division of the probate court has acquired formal jurisdiction of a child, and it appears to the probate court that, because of the circumstances of the case or because the child's condition might be benefited, the court may make a temporary commitment to the department and direct that the child be taken to a facility of the Michigan children's institute for observation for a period not to exceed 90 days. Before the expiration of this order of observation, the superintendent of the institute shall report to the probate court the results of the observation of the child. If the superintendent reports to the probate court that the order of observation should be extended or that the child is in need of treatment for emotional disturbance that does not require hospital care and for which the institute has facilities, then the court may extend the temporary commitment and continue the observation order or establish a treatment period for the child to any date prior to the nineteenth birthday of the child. If the child has ceased to be a ward of the court, written consent of the person or persons lawfully having custody of the child shall be secured. Before the expiration of this extended order of observation or treatment, the superintendent shall report to the probate court the results of the observation or treatment of the child and an opinion stating what disposition can be made of the child. Before any child is sent to a facility of the institute for observation, the superintendent of the institute shall notify the probate court that there is room to receive the child and shall designate the facility of the institute for the reception of the child. The commission may by regulation establish conditions for the reimbursement of the expense of caring for the child while under the supervision of the institute if the parents or other persons responsible for the child's support are financially able to pay reasonable costs of the child's care.

    (2) The superintendent of the institute has the power to make decisions on behalf of a child committed to the institute. The attorney general or his or her representative shall represent the Michigan children's institute superintendent in any court proceeding in which the superintendent considers such representation necessary to carry out his or her duties under this act.

    (3) As used in this act, "department" means the department of human services.