Mich. Comp. Laws § 712B.31: Agreements.

Sec. 31.

(1) The state is authorized to enter into agreements with tribes in this state regarding the care and custody of Indian children, funding of the care and custody of Indian children, and jurisdiction over child custody proceedings, including agreements that may provide for transfer of jurisdiction on a case-by-case basis and agreements that provide for concurrent jurisdiction between the state and Indian tribes.

(2) Unless the agreement provides otherwise, both of the following apply:

(a) The agreements described in subsection (1) may be revoked by either party upon 180 days' written notice to the other party.

(b) Revocation of an agreement does not affect any action or proceeding over which the court already has jurisdiction.