We investigated the effects of semantic predictability on children's preservation of the /t/-/d/ phonemic voice contrast in American English. In Experiment 1, a total of 36 seven-, nine-, and twelve-year-olds produced minimal pairs differing in intervocalic /t/ and /d/ in semantically biasing and semantically neutral passages. The seven-year-olds preserved the phonemic contrast in both passage types. However, for the nine- and twelve-year-olds, total word duration and preceding vowel duration preserved the /t/-/d/ contrast, but this interacted with semantic predictability. The contrast was preserved in the biasing and not in the neutral passages. The production results from the older children replicated previous findings from adults, demonstrating that semantic predictability influences speech production at both a lexical and a segmental level. In Experiment 2, listeners identified the tokens produced in Experiment 1. The identification results suggested that differences produced by speakers may not necessarily have a functional role for listeners. An interactive activation framework is proposed to account for the semantic effects on older children's and adults' production. For the youngest children, however, we suggest that pragmatic compensation and task demands interact with the effects of interactive activation.