In the United States, civil commitment language typically permits involuntary hospitalization of individuals with mental illness for one of three purposes: suicidal danger to self, homicidal danger to others, or danger to self as a result of grave disability, which prevents an individual from being able to secure basic necessities such as food, clothing, or shelter. As with patients who have decompensated schizophrenia or severe and immobilizing depression who meet dangerousness criteria, individuals with severe substance use disorders may be considered eligible in some U.S. states for involuntary hospitalization when they become gravely disabled. In New York State, the definition of mental illness for civil commitment purposes (MHL x 1.03) is very broad and allows for considerable discretion. However, the law does not reference substance use disorders. Although many clinicians may have assumed that substance use disorders did not qualify as commit table mental illnesses, no case law existed until 1995 to guide interpretation. In the Matter of Michael S. is a case that came before a West chester County, New York, court in 1995 (2). In this case, a father and doctor had petitioned a lower court to involuntarily admit an opiate-addicted patient for treatment. The lower court dismissed the complaint, writing, “There is no medical evidence to equate mental illness with drug addiction.” A second court did not comment on this matter until 2010. In Lawlor v. Lenox Hill Hospital, a patient brought a medical malpractice claim against Lenox Hill Hospital alleging that Lenox Hill failed to psychiatrically evaluate and involuntarily treat a patient who had been medically admitted for alcohol related injuries (3). The court again dismissed the complaint, stating, “Alcoholism is not considered a mental illnessunder [NewYorkStatestatute] and a person cannot be involuntarily confined under that statute solely for treatment of alcoholism.” A subsequent case has now relied on Lawlor, excluding “alcoholism” as a committable mental illness (4). These court rulings, however, have limited precedential authority and are not applicable throughout the state—or even throughout New York City. The rulings give little clarification as to what qualifies as a mental illness in New York State. The ambiguity surrounding criteria for the commitment of addicted persons in New York may hinder clinician attempts to treat this complex population. State statutes that do not explicitly comment on substance use disorders within their definitions of mental illness for civil commitment may complicate efforts by families and providers to secure inpatient treatment for appropriate patients. Consequently, in many states it is legally difficult—or frequently believed by practitioners to be difficult (5,6)—to hospitalize patients gravely disabled by substance use disorders who do not agree to treatment.