Recent longitudinal approaches to second language (L2) pronunciation development have prioritized developmental trajectories, highlighting individual variation in phonetic learning over time. Aligning with this research paradigm, the present study examined voice onset time (VOT) production in Spanish/b/and/p/ over two semesters of elementary language instruction. Twenty-six native speakers of English who were novice learners of Spanish completed two L2 production tasks five times and an English production task once, designed to ascertain the frequency with which they prevoiced English voiced stops. Growth curve modeling revealed that linear and quadratic functions most accurately captured participants’ L2 VOT development insofar as more gains occurred during the first half of the study. Speakers’ propensity to prevoice in the native language also predicted prevoicing in L2 Spanish/b/. However, individual results varied, including near-native learners and asymmetrical developers, individuals who improved their production of /p/but not/b/. These results are interpreted within the frameworks of the Speech Learning Model and L2 Perceptual Assimilation Model.