Michigan Compiled Laws, Chapter 333. Health § 333.5678

(a) A patient may revoke the POST form at any time and in any manner that the patient is able to communicate his or her intent to revoke the POST form. If the patient's revocation is not in writing, an individual who witnesses the patient's expressed intent to revoke the POST form shall describe in writing the circumstances of the revocation, sign the writing, and provide the writing to the individuals described in subsection (2), as applicable.

(b) The patient representative may revoke the POST form at any time the patient representative considers revoking the POST form to be consistent with the patient's wishes or, if the patient's wishes are unknown, in the patient's best interest.

(c) If a change in the patient's medical condition makes the medical orders on the POST form contrary to generally accepted health care standards, the attending health professional may revoke the POST form. If an attending health professional revokes a POST form under this subdivision, he or she shall take reasonable actions to notify the patient or the patient representative of the revocation and the change in the patient's medical condition that warranted the revocation of the POST form.

(a) The attending health professional.

(b) A health professional who is treating the patient.

(c) The health facility that is directly responsible for the medical treatment or care and custody of the patient.

(d) The patient.