For a person to create a valid advance health care directive, a person must be 18 years old, and of sound mind and capacity. Two qualified adult witnesses or a notary public is needed to sign and validate an advance health care directive. Their signature proves that they acknowledge the person creating the document is competent and acting out of their own will. A qualified witness cannot be a health care agent, alternate health care agent, supervising health care provider, or an employee of a health care facility.
Family members, by blood, marriage, or adoption cannot witness an advance health care directive, either. Advance health care directives can be revoked or changed at any point. In order to revoke an advance health care directive, a person must inform their health care provider in person or via writing. The creation of a new advance health care directive will revoke any prior advance health care directive.