Mich. Comp. Laws § 449.1301

Sec. 301. (a) After the filing of a limited partnership's original certificate of limited partnership, a person may be admitted as an additional limited partner: (1) In the case of a person acquiring a partnership interest directly from the limited partnership, upon the compliance with the partnership agreement or, if the partnership agreement does not so provide, upon the written consent of all partners. (2) In the case of an assignee of a partnership interest of a partner who has the power, as provided in section 704, to grant the assignee the right to become a limited partner, upon the exercise of that power and compliance with any conditions limiting the grant or exercise of the power. (b) In each case under subsection (a), the person acquiring the partnership interest becomes a limited partner only upon amendment of the certificate of limited partnership reflecting that fact.