Templatic morphology involves the appearance of a fixed shape on a morpheme in a specific morphological context. This paper makes two claims: the morphological context of a template is syntactically cyclic, resulting in recursive prosodic word structure, and the shape of a template results from prosodic well-formedness conditions on the internal prosodic word. Templatic morphology in Chukchansi Yokuts illustrates these claims: affixes that trigger templates transfer the root to the phonology before other material is transferred, so that the root forms a prosodic word which is internal to the whole word. Roots with one underlying vowel are augmented to meet a disyllabic minimality requirement on prosodic words; the resulting disyllable forms a light–heavy iamb, to optimally satisfy Chukchansi parsing requirements. Templatic morphology falls out from the predictable interaction of the syntax–phonology interface and general phonological properties of a language, and needs no special apparatus or diacritics.