The "Michigan Medical Treatment Decisions Act" establishes a framework for making medical treatment decisions on behalf of patients who are unable to participate in such decisions. The bill defines key terms such as "attending physician," "guardian," "patient advocate," and "surrogate," and outlines the hierarchy of individuals who may make medical treatment decisions, prioritizing spouses, adult children, and other relatives. It stipulates that these decisions can only be made when the patient is unable to participate, does not have a patient advocate or guardian available, and after attempts have been made to communicate with the patient regarding the decision-makers and the treatment options.

Additionally, the bill prohibits certain types of medical treatments from being authorized by the designated decision-makers, including the withholding or withdrawing of treatment that would result in death, sterilization, termination of pregnancy, and admission to specific types of facilities. It also clarifies that healthcare providers implementing decisions made under this act will be liable as if the patient had made the decision themselves. The act does not override existing advance directives or patient advocate designations, ensuring that previously expressed wishes regarding medical treatment are respected.