I have been with my significant other for decades, but we are not married. If I become unable to make decisions for myself, will she be the one appointed to serve as my medical and financial fiduciary?

Not necessarily. If you become sick and are not legally married, your significant other does not have statutory priority under Michigan law to serve as your guardian or conservator. Your parents, children, and siblings all have priority to serve in this capacity. Therefore, you could wind up having an undesirable family member being appointed by the probate court to make all of your important life-altering decisions. A power of attorney is a critical document not only to address this situation, but to help avoid probate court in the event you become ill or incapacitated in general.