Michigan Compiled Laws, Chapter 700. Estates and Protected Individuals Code § 700.3603

Sec. 3603. (1) A bond is not required of a personal representative appointed in informal proceedings, except in any of the following circumstances:

(2) Except as otherwise provided in this subsection, in a formal proceeding, the court may order bond at the time of the personal representative's appointment. The court shall not order bond of the personal representative in the formal proceeding if the will relieves the personal representative of bond, unless an interested person requests bond and the court is satisfied that bond is desirable. If a will in a formal proceeding requires bond, bond may be dispensed with if the court determines it is unnecessary.

(3) Bond is not required of a personal representative who deposits, as determined by the court, cash or collateral with the county treasurer to secure performance of the fiduciary duties.