We emphasize the value of a developmental framework for adolescent diagnosis and clinical formulation. Clinical use of diagnostic approaches constructed for either children or adults risks misunderstanding, and perhaps even misdiagnosing, symptoms and experiences that may be tied to the psychological, social, and biological changes inherent in this phase of life. To illustrate a more developmentally attuned approach to clinical formulation, we apply the adolescent section of the Psychodynamic Diagnostic Manual, 2nd Edition (PDM-2) to 2 clinical cases, 1 an early adolescent and 1 a late adolescent. We discuss them in terms of 3 PDM axes: mental functioning (MA Axis), emerging personality patterns (PA Axis), and subjective experience of symptom patterns (SA Axis).