Three major legal mechanisms exist for providing involuntary community treatment to people who are violent and mentally disabled: outpatient commitment, preventive commitment, and conditional release from a hospital. In most states, predicted deterioration is either the explicit or the de facto criterion for involuntary community treatment. However, the constitutionality of this standard has been the subject of considerable debate, centering on whether involuntary treatment in the community requires a showing of imminent dangerousness and an overt act of dangerousness and whether a person who is not dangerous solely because of treatment may be committed. The author suggests that the predicted deterioration standard is constitutional, but only if it is accompanied by limitations on the duration of commitment and proof that involuntary treatment is necessary to prevent danger to self or others. The author also discusses whether a person committed under the predicted deterioration standard has the right to refuse treatment and whether persons hospitalized after being committed to involuntary community treatment should receive a hearing.