Involuntary civil commitment is the admission of individuals against their will into a mental health unit. Generally speaking, there are three reasons why an individual would be subject to involuntary civil commitment under modern statutes: mental illness, developmental disability, and substance addiction. In the case of mental illness, dangerousness to self or others defines the typical commitment standard, with almost all states construing the inability to provide for one's basic needs as dangerousness to self. In terms of process, every state provides for a hearing, the right to counsel, and periodic judicial review, while most states have statutory quality standards for treatment and hospitalization environment.
Source: Ralph Reisner, Christopher Slobogin, and Arti Rai, Law and the Mental Health System: Civil and Criminal Aspects (2009), pp. 704-705.