Advance Medical DirectivesAn advance medical directive is a legal medical guideline that explains a patient’s health care treatment preferences. It also includes a statement designating a surrogate decision-maker in the event that a patient should become unable to make medical decisions on his or her own behalf. These generally fall into three categories: living will, power of attorney, and health care proxy. All fifty states and the District of Columbia have passed laws to legalize the use of living wills, health care proxies and/or the durable power of attorney. The U.S. federal government has validated state laws on advance directives through the 1991 Patient Self-Determination Act.