National trends that are changing the practice ofemergency psychiatry include the rapid growth in the number of psychiatric emergency services, the relationship between privatization of psychiatric care and increased emergency visits, and the growing specialized populations visiting psychiatric emergency services. To meet the challenges posed by the increasing numbers of homeless mentally ill persons, children, and dual diagnosis patients who seek emergency services, the psychiatric emergency field is developing innovative program models such as outreach teams, psychiatric diversion beds, and crisis follow-up care. This column reviews trends in the field and outlines some of these models.