Living wills allow people to explain in writing which medical treatments they do or do not want if they have a serious or terminal illness and are too ill to voice their wishes. Surveys show that many people in the United States favor having living wills. Many say that they would limit certain medical treatments if told that they were terminally ill. Also, many would prefer to die at home rather than in a hospital. However, only 20% of people in the United States have a living will. Evidence that these wills influence end-of-life care is mixed and sometimes scant. In particular, no studies address whether having a living will influences where people die.