Agile Transformation (AT), the process of adopting agile methods and practices in organizational settings, has received grappling attention in research due to its extensive emergence in practice. Although the complexity of ATs is well known and its use cases widespread, research has not yet developed a comprehensive classification of AT. This lack limits the comparability of existing studies and our possibility to draw theoretical generalizations from their results. In this paper, we fill this gap by presenting a taxonomy for AT based on a systematic literature review. We abstracted the taxonomy in an analysis of 92 articles, including empirical and theoretical papers as well as experience reports. We contribute to the existing literature by providing a taxonomy that presents an analytical theory, offering a characterization of ATs which helps researchers and practitioners analyze ATs, identify how they differ, and provide insight into combinations of agile characteristics.