(1) A parent or guardian of any child whose legal custody has been transferred by the court to an individual, agency, or institution, except a secure youth corrections facility, may petition the court for restoration of custody or other modification or revocation of the court's order, on the ground that a change of circumstances has occurred which requires such modification or revocation in the best interest of the child or the public.

(2) The court shall make a preliminary investigation. If the court finds that the alleged change of circumstances, if proved, would not affect the decree, it may dismiss the petition. If the court finds that a further examination of the facts is needed, or if the court on its own motion determines that the decree should be reviewed, it shall conduct a hearing. Notice shall be given to all persons concerned. At the hearing, the court may enter an order continuing, modifying, or terminating the decree.

(3) (a) A parent may not file a petition under this section after the parent's parental rights have been terminated in accordance with Part 5, Termination of Parental Rights Act. (b) A parent may not file a petition for restoration of custody under this section during the existence of a permanent guardianship established for the child under Subsection 78A-6-117(2)(z).

(a) A parent may not file a petition under this section after the parent's parental rights have been terminated in accordance with Part 5, Termination of Parental Rights Act.

(b) A parent may not file a petition for restoration of custody under this section during the existence of a permanent guardianship established for the child under Subsection 78A-6-117(2)(z).

(4) An individual, agency, or institution vested with legal custody of a child may petition the court for a modification of the custody order on the ground that the change is necessary for the welfare of the child or in the public interest. The court shall proceed upon the petition in accordance with Subsections (1) and (2).