This chapter explores all the stages in the United States criminal justice process in which a defendant or prisoner may become incompetent and a potential candidate for involuntary treatment to restore the subject’s competence, including competence to stand trial, competence to plead guilty and to waive trial rights, competence to represent himself, and competence to be sentenced. Other legal systems may treat this as primarily a mental health law question addressed best by mental health laws, but in the United States, it is a criminal law question, although some courts are very deferential to the judgement of mental health professionals. The chapter then surveys the law and offers a normative set of recommendations for when involuntary treatment is justified, as well as recommendations for the disposition of the subject if involuntary treatment is not justified or is unsuccessful.