Interpersonal Psychotherapy Adolescent Skills Training (IPT-AST) is an evidenced-based intervention for the prevention of depression in adolescents. IST-AST is a group adaptation of Interpersonal Psychotherapy for Depressed Adolescents (IPT-A) that has been provided in school-based settings and has extensive evidence for reducing elevated depressive symptoms in adolescents and decrease their risk for developing a clinically significant episode of major depression. This chapter provides the rationale for IST-AST and the adaptations that expand this intervention for treatment delivery in group settings. It clearly describes aspects of implementing IPT-AST at both the individual and group level for participating adolescents, while outlining the goals and strategies used in each session. The aspects of administering IST-AST are highlighted in a case vignette that illustrates both the individual adolescent and the group experience. Lastly, the chapter includes an updated overview of the empirical evidence that supports the use of IPT-AST as an effective and evidence-based psychological intervention for the prevention of depression in adolescents.