Mich. Comp. Laws § 700.1003

Sec. 3. (1) Subject to subsections (2), (3), and (4), this act applies to all of the following: (a) A fiduciary acting under a will or power of attorney executed before, on, or after the effective date of this act. (b) A personal representative acting for a decedent who died before, on, or after the effective date of this act. (c) A proceeding involving a conservator commenced before, on, or after the effective date of this act. (d) A trustee acting under a trust created before, on, or after the effective date of this act. (2) This act applies to a digital custodian if the user resides in this state or resided in this state at the time of the user's death. (3) This act does not impair an accrued right or an action taken in a proceeding before the effective date of this act. (4) This act does not apply to a digital asset of an employer used by an employee in the ordinary course of business.