This article reports a post hoc analysis conducted as part of a larger study in which 61 typically developing, 3-, 4-, and 5-year-olds were assessed in phonological awareness (PA), vocabulary (i.e., receptive, expressive, and definitional), and grammatical skill at baseline and 3, 6, and 9 months later. The larger study's purpose was to shed light on the theory of lexical reorganization claim that increases in receptive vocabulary provide the basis for PA development. Its results showed that expressive vocabulary accounted for additional PA growth in 4- and 5-year-olds but not in 3-year-olds. The post hoc study involved a closer analysis of PA growth in relation to expressive vocabulary. Its results suggest that increases in receptive vocabulary might be necessary as a foundation for initial PA development but that expressive-level vocabulary might be needed to hold words in memory to perform complex manipulations required in higher level PA tasks.