The success of open source software (OSS) projects heavily depends on voluntary participation by a large number of developers. Developers new to an OSS community must participate by engaging in community interactions before they are qualified by the community as core developers. This exploratory study examines new peripheral developers’ temporal participation behavior and its impacts on the time taken to attain core developer status. Using the novel latent class growth modeling approach on 133 peripheral developers across 40 OSS projects, we found that these peripheral developers differed in the initial levels and growth trajectories of participation, and distinct classes of participation behavior were identified. We also found that different classes of developers differ in their time taken to attain core developer status. Implications to research and practice are discussed.