This presentation will initially introduce the hierarchical-dimensional model of psychopathology, which evolved in part as a reaction to limitations seen with conventional, categorical diagnostic systems. It will briefly review models elucidating the current structure of psychopathology (as presently known), with the caveat that we are still in the infancy stage of this research. Using Spearman's g-factor of general intelligence as an analogue, the presentation will then focus on the higher-order structures that have been shown to effectively explain the covariation/comorbidity seen in common psychiatric disorders: Internalizing, Externalizing, and Reality-Impairing dimensions, which in tum map into a global dimension, the p-factor. The clinical implications of assessing psychopathology in this manner will be discussed and will be followed by a review of available instruments that evaluate psychopathology at various levels of this model. The presentation will conclude with several clinical examples of how to integrate these assessment findings into our conceptualization of clinical formulation and diagnosis.