Mich. Comp. Laws § 557.253
Any property which, at the time this act takes effect, constitutes community property by virtue of the provisions of Act No. 317 of the Public Acts of 1947 shall continue to be community property and remain subject to the provisions of said act and for such purpose said act shall continue in force: Provided, That, except where the conveyance or other instrument of title under which the same was acquired or other evidence of ownership thereof expressly states the intention that such property shall be community property, any such property shall, upon the expiration of 1 year after the time this act takes effect, be deemed to be the separate property of the husband or the wife, or both, according to the name or names set forth in the conveyance or other instrument of title under which such property was acquired or other evidence of ownership thereof, unless, within such 1 year period, either spouse having an interest therein, or any of the devisees, legatees, heirs or distributees of either of them who shall have died prior to or during the running of such 1 year period, shall file notice of claim that such property constitutes community property.
Such notice of claim, to be effective, shall be in writing, shall contain a description of each item of property to which the same relates, shall be executed by the party making the same in the manner required for the execution of deeds and shall be filed in the office of the register of deeds for the county in which the spouse by whom, or in whose behalf, the same is made resides at the time of the filing thereof, or, in the event that such spouse shall have died, for the county in which such spouse resided at the time of death. In the event that such notice of claim relates to real property located in any other county or counties, to be effective as to such property, a duplicate original of such notice of claim shall also be filed in the office of the register of deeds for each such county.
No disability of any kind or lack of knowledge on the part of anyone shall suspend the running of the time for filing such notice of claim, but such notice may be executed and filed by any other person acting in behalf of any party by whom such notice of claim may be filed who is under a disability or otherwise unable to make such claim in his or her own behalf.
MCL 557.253