The difficulty of determining decision-making capacity gives rise to errors at two extremes: the competent patient's ability to control health care decisions is denied; or an incapacitated patient is not protected from making a decision that is harmful or that is not an expression of their values. This module identifies the components of decision-making capacity in a clinical setting, ethical issues arising from capacity assessment, methods of maximizing decision-making capacity to impose the least restrictive intrusion on an individual's autonomy, and the process of surrogate decision-making for adults and minors.