Shared decision making respects patient autonomy and allows patients to select how much they wish to become involved in various health care decisions. Advance care planning allows a person to document preferences that can become operative at a later time when the person has lost decision-making capacity. Structured methods exist for assessing the presence or absence of decision-making capacity, but some subjectivity cannot be eliminated from these assessments. An ethical challenge in the care of older patients who have diminished capacity is to show respect for their previously expressed wishes and for their present, experienced quality of life.