A legal document that allows individuals to name someone they know and trust to make health care decisions for them if, for any reason and at any time, the individual becomes unable to make or communicate those decisions. Some states limit the age at which such a proxy may be established and prohibit certain persons, such as an estate administrator or an employee of a health care facility in which the person making the proxy is a resident, from being appointed to make health care decisions unless he or she is related to the person by blood, marriage, or adoption.