This article introduces the National Educational Panel Study (NEPS). This German longitudinal study produces a vast amount of data for the scientific community, and researchers all around Europe are invited to use the data to address various research questions empirically. Therefore, the authors provide information about the purpose as well as the design of this educational study that has just released data from several starting cohorts, ranging from newborns to adults. As the authors have coordinated the starting cohort of students in lower-secondary school, this target group will be introduced in more detail, with the implementation of NEPS's design being outlined, as well as the tests and survey contents. The analytical potentials are exemplified by the authors' stage-specific research on German-language instruction, the development of orthography competence, and engagement in reading and orthography in lower-secondary school. An overview of different modes of access to the available data completes this research report.