Michigan Compiled Laws, Chapters 701 to 713 Probate Code § 710.46

Sec. 46. (1) Upon the filing of an adoption petition, the court shall direct a full investigation by an employee or agent of the court, a child placing agency, or the department.The court may use the preplacement assessment described in section 23f of this chapter and may order an additional investigation by an employee or agent of the court or a child placing agency. The following shall be considered in the investigation:

(2) A written report of the investigation shall be filed within 3 months after the order for investigation.

(3) If the adoptee has been placed for foster care with the petitioner for 12 months or longer and the foster family study was completed or updated not more than 12 months before the petition was filed, the court, upon motion by the petitioner, may waive the full investigation required by this section. The foster family study, with information added as necessary to update or supplement the original study, may be substituted for the written report required under subsection (2).