You can revoke or change an Advance Health Care Directive at any time.  To revoke the entire form, including the appointment of your agent, you must inform your treating health care provider personally or in writing.  Completing a new Advance Health Care Directive will revoke all previous directives.  In addition, if you revoke or change your directive, you should notify every person or facility that has a copy of your prior directive and provide them with a new one.