I heard about a legal document called a right-to-die form, where you state that if you become a vegetable your family or doctor should pull the plug. Can you tell me about this form?
The document you want is a health care directive -- known in various states as a living will, directive to physicians, or health care declaration. A person making the document can use it to set out wishes about what life-prolonging treatment should be withheld or provided if he or she becomes unable to communicate those wishes. A doctor who receives a properly signed and witnessed or notarized directive is duty-bound to either honor its instructions, or to make sure the patient is transferred to the care of another doctor who will honor them.
Because health care directives came from the right-to-die movement, in which the focus was dying without medical intervention, many people tend to think of them as documents appropriate only for directing that life-prolonging procedures should be withdrawn or withheld.
However, these documents should more correctly be viewed as a way to direct doctors to provide you with whatever type of medical care you want, within reality and reason. For example, some people want to reinforce that they would like to receive all medical treatment that is available -- and a health care directive is the proper place to specify that.
You can find the health care forms you need for your state in Nolo's Quicken WillMaker. The software includes detailed instructions and helpful guidance in completing your documents.