MCL 333.26424
4. Protections for the Medical Use of Marihuana.
Sec. 4. (a) A qualifying patient who has been issued and
possesses a registry identification card shall not be subject to arrest, prosecution, or penalty in any manner, or denied any right or privilege, including but not limited to civil penalty or disciplinary action by a business or occupational or professional licensing board or bureau, for the medical use of marihuana in accordance with this act, provided that the qualifying patient possesses an amount of marihuana that does not exceed 2.5 ounces of usable marihuana, and, if the qualifying patient has not specified that a primary caregiver will be allowed under state law to cultivate marihuana for the qualifying patient, 12 marihuana plants kept in an enclosed, locked facility. Any incidental amount of seeds, stalks, and unusable roots shall also be allowed under state law and shall not be included in this amount.
(b) A primary caregiver who has been issued and possesses a registry identification card shall not be subject to arrest, prosecution, or penalty in any manner, or denied any right or privilege, including but not limited to civil penalty or disciplinary action by a business or occupational or professional licensing board or bureau, for assisting a qualifying patient to whom he or she is connected through the department's registration process with the medical use of marihuana in accordance with this act, provided that the primary caregiver possesses an amount of marihuana that does not exceed:
(1) 2.5 ounces of usable marihuana for each qualifying patient to whom he or she is connected through the department's registration process; and
(2) for each registered qualifying patient who has specified that the primary caregiver will be allowed under state law to cultivate marihuana for the qualifying patient, 12 marihuana plants kept in an enclosed, locked facility; and
(3) any incidental amount of seeds, stalks, and unusable roots.
(c) A person shall not be denied custody or visitation of a minor for acting in accordance with this act, unless the person's behavior is such that it creates an unreasonable danger to the minor that can be clearly articulated and substantiated.
(d) There shall be a presumption that a qualifying patient or primary caregiver is engaged in the medical use of marihuana in accordance with this act if the qualifying patient or primary caregiver:
(1) is in possession of a registry identification card; and
(2) is in possession of an amount of marihuana that does not exceed the amount allowed under this act. The presumption may be rebutted by evidence that conduct related to marihuana was not for the purpose of alleviating the qualifying patient's debilitating medical condition or symptoms associated with the debilitating medical condition, in accordance with this act.
Maybe not as cut and dry but it is there IMO
All of it can be found here
http://www.legislature.mi.gov/(S(af...Object&objectName=mcl-Initiated-Law-1-of-2008