Michigan Compiled Laws, Chapter 700. Estates and Protected Individuals Code § 700.3914

Sec. 3914. (1) Subject to the rights of creditors and taxing authorities, competent successors may agree among themselves to alter the interests, shares, or amounts to which they are entitled under the will of the decedent, or under the laws of intestacy, in any way that they provide in a written agreement executed by all who are affected by its provisions. If there is, or may be, an interested person to the agreement who is a minor or incapacitated individual or if there is an inalienable estate or future contingent interest, after notice to the representative of the individual or interest as provided by supreme court rule, the court having jurisdiction of the matter may, if the agreement is made in good faith and appears just and reasonable for the individual or interest, direct the representative of the individual or interest to sign and enter into the agreement. The personal representative shall abide by the agreement's terms subject to the personal representative's obligation to administer the estate for the benefit of creditors, to pay all taxes and costs of administration, and to carry out the fiduciary office's responsibilities for the benefit of a successor of the decedent who is not a party.

(2) A personal representative of a decedent's estate is not required to see to the performance of a trust if the trustee of the trust is another person who is willing to accept the trust. Accordingly, a trustee of a trust created by will is a successor for the purposes of this section. Nothing in this section relieves a trustee of a duty owed to a trust beneficiary.