A medical power of attorney is made to give you the power to appoint some one to carry out your medical wishes in the event you can't communicate those decisions yourself, or lack the mental capacity to do so. In short, a medical power of attorney is a plan made in anticipation of a medical emergency. The person you appoint to carry out your wishes will have the legally authority to do so If you appoint them as your 'agent' in your legal medical power of attorney form. Obviously whoever you appoint as your 'agent' should be some one you trust to actually enforce your wishes in the event of a serious accident.

Whomever you choose as your 'agent', realize that individual will be in charge of making your medical decisions when you’re incapacitated. An agent officially has the legal authority to make your medical decisions if you appointed them as your agent in your medical power of attorney if your physician certifies in writing that you’re incompetent.

Legally, a medical power of attorney is not effective unless the principal (person who the will is made for) signs a disclosure statement that they understand and have completely read. Usually your state's medical power of attorney will require there to be a witness sign along with you to verify you did read and understand it. A qualified witness is some one who is competent, an adult, and is not related to the principal. Also the witness cannot be a partner of business or a witness related to your physician.

You can revoke your medical power of attorney at any time by notifying the agent and principal's health care provider of his or her intent to revoke the document. This is usually done officially with a 'revocation of power of attorney form'. Also, if you appointed your spouse and you two get divorced her legal authority as your 'agent' is automatically revoked.