Idaho Code § 16-1509A: Dissolution of adoption.

An adoption may be dissolved, upon petition, with the agreement of both the adoptee and the adopting parent, when the adopting parent was the spouse of a natural parent, and the marriage of the natural parent and adoptive parent was terminated. If the petition for dissolution occurs after the death of the adoptive parent, the court shall, in the finding of dissolution, specify the effect upon rights of inheritance. The court must determine that avoidance of statutory care is not the purpose of the dissolution, unless the court finds grounds to waive this finding. An action to obtain a decree of dissolution of adoption may be commenced at any time after the adoptee reaches twenty-one (21) years of age.