MST is an intensive family- and community-based treatment that addresses the multiple determinants of serious antisocial behavior in juvenile offenders. MST addresses the factors associated with delinquency across a youth's key settings, or systems (e.g., family, peers, school, neighborhood). Using the strengths of each system to foster positive change, MST promotes behavior change in the youth's natural environment. Four major points separate MST from other treatments for antisocial behavior: research, treatment theory, implementation, and focus on long-term outcomes. MST is similar to other community-based programs in its use of a "family preservation" model of service delivery. In this model, services typically are provided to the family, targeted to families with children at risk of being placed out of the home, time-limited (1 to 5 months), flexibly scheduled and delivered in the home, tailored to family members' needs, provided in the context of a family's values, beliefs and culture, and available 24 hours a day, 7 days a week. Family preservation services are sometimes described as "intensive" because families are frequently seen from 2 to 15 hours per week. Bibliography