In Cruzan, the Supreme Court held that the refusal of treatment is a constitutionally protected right and that the methods for permitting its exercise should be crafted by the laboratory of the states. In June 1990, when the court ruled, there already existed a large and complex body of law concerned with the refusal of treatment which differed, sometimes considerably, from state to state. Generally, withholding or withdrawing life-sustaining treatment has been accepted by the states, but different systems of justification have been used.
Competent people are able to make decisions to refuse any form of medical treatment, regardless of their medical condition; competent people can also prepare written instructions describing the medical treatment they would want to receive in the future if incompetent, which have been endorsed by both state courts and legislatures.