Mich. Comp. Laws § 557.204

Sec. 4. All property of every kind, character, or description acquired by either the husband or the wife, or both, after marriage, or on or after the effective date of this act, whichever is later, except that which is defined as the separate property of either or the separate property of both in sections 1, 2 and 3 of this act, shall be deemed the community property of the husband and wife, and each shall be vested with an undivided 1/2 interest therein. The respective interest of the husband and the wife in such community property shall be present, existing, and equal interests and shall arise as an incident of marriage.