For some persons who are facing terminal illness, severe permanent disability, or extreme old age, suicide may seem to be a rational choice. Suicide prevention services, however, do not provide for suicide as a sane, honorable choice in such circumstances. This paper identifies 17 specific considerations a mental-health professional may use to help such a person explore whether suicide would be rational or irrational. These considerations are formulated without antecedent bias towards prevention and without interpreting interest in suicide as evidence of depression or mental illness. Dying, severely disabled, and aged persons considering suicide on what seem to them to be rational grounds may thus trust and consult mental-health professionals about their plans.