Michigan Compiled Laws, Chapter 700. Estates and Protected Individuals Code § 700.2904

Sec. 2904. (1) Except as provided in section 2905,  1 if a disclaimed interest arises under a will or trust created by will, or by the laws of intestacy, the disclaimer must be delivered after the death of the owner of the property and before any event described in section 2910.  2 If a disclaimed interest arises under a will or by the laws of intestacy, the disclaimer must be delivered to the personal representative of the deceased owner's estate. If a disclaimed interest arises under a trust created by will, the disclaimer must be delivered to the trustee of the trust created by will or, if a trustee has not been appointed, to the personal representative of the deceased owner's estate.

(2) Except as provided in section 2905, if a disclaimed interest arises under a governing instrument other than a will or trust created by will, the disclaimer must be delivered after the effective date of the governing instrument and before any event described in section 2910. A disclaimer under this subsection must be delivered in 1 of the following manners: