A living will, also called a treatment directive, is a type of advance directive that documents personal wishes about end-of-life medical treatment in case decision-making or communication abilities are lost. A living will specifies the conditions under which certain kinds of treatment or life-support measures would or would not be wanted.

A living will can be changed or revoked at any time and will not take effect until a person is no longer able to make or communicate decisions. Copies of living wills should be given to and discussed with a person's health professional and family members.