The Arizona-4 scores help clinicians identify individuals who are in need of speech sound services and develop treatment plans for them. It measures speech intelligibility, articulatory impairment, and phonological impairment in one quick, easy to use assessment. The fourth edition of this widely used assessment retains the strengths of its predecessors and adds features that enhance its effectiveness in identifying individuals who have speech sound disorders. New norms, refined measurement properties, and the addition of connected-speech and phonology tests help clinicians identify individuals who may benefit from speech sound services. Supplemental qualitative tasks facilitate deeper interpretation of the scores and help clinicians develop treatment plans that are targeted to the individuals needs.