Maturity models (MM) enjoy great popularity among scholars and practitioners, particularly for addressing the novel challenges in IS design and management of IS projects. However, MM research is harshly criticized by rigor-centered academics because of methodological shortcomings. This is because existing design principles for MM development often are insufficiently applied. In this research, we conduct a scoping review of the academic MM literature. Informed by the analysis of MM literature, we pinpoint existing methodological weaknesses of MM research and offer suggestions on how to improve extant design principles for MM development. The presented guideline extensions apply to the complete MM design process from problem definition to results presentation and cover eight design principles. Our results contribute to increased relevance and rigor in MM research. Further, they motivate further research on empirically and longitudinally validating MM’s impact in practice and on the mechanisms of how MM supports organizational learning.