POWER OF ATTORNEY
What is an Instrument Appointing Guardian/Medical Treatment Decision Maker?

A Power of Guardian or Instrument Appointing Medical Treatment Decision Maker (depending on your state or territory) authorises a person or persons to make medical treatment decisions on your behalf if and when you are unable to make these decisions.

For example: the instrument appointing the decision maker appoints the person who will carry out your instructions you have indicated in the advance care directive.