Section 9100 Of Chapter 6. Vacation Of Adoption From California Family Law Code >> Division 13. >> Part 2. >> Chapter 6.

. (a) If a child adopted pursuant to the law of this state shows evidence of a developmental disability or mental illness as a result of conditions existing before the adoption to an extent that the child cannot be relinquished to an adoption agency on the grounds that the child is considered unadoptable, and of which conditions the adoptive parents or parent had no knowledge or notice before the entry of the order of adoption, a petition setting forth those facts may be filed by the adoptive parents or parent with the court that granted the adoption petition. If these facts are proved to the satisfaction of the court, it may make an order setting aside the order of adoption.
  (b) The petition shall be filed within five years after the entry of the order of adoption.
  (c) The court clerk shall immediately notify the department at Sacramento of the petition. Within 60 days after the notice, the department shall file a full report with the court and shall appear before the court for the purpose of representing the adopted child.