<p>Digital transformation (DT) is a major challenge for organisations. Digital maturity models (DMMs) and digital transformation maturity models (DTMMs) have been developed to help decision-makers in making decisions about DT. The terms DMM and DTMM are used interchangeably and have evolved in parallel, and this duality has generated confusion for both researchers and practitioners. The goal of this paper is to generate more prescriptive knowledge for understanding these maturity models related to digital phenomena. For this purpose, we review 60 papers that discuss DMMs and DTMMs using the context-intervention-mechanism-outcome (CIMO) theoretical framework of analysis. The results reveal four fundamental mechanisms that explain how maturity models in this field of study are constructed and used: models focused on the outcomes of digital transformation (DMMs), models centred on the process of digital transformation (DTMMs), mixed models (focusing on both outcomes and processes associated with DT), and strategic models, which evaluate the outcomes, process, and strategy of DT. Considering the differences between DMMs and DTMMs, the paper identifies theoretical and methodological gaps in current research while providing valuable results for researchers in developing new models, and for practitioners in selecting the most appropriate maturity model for their organisations in their DT path.</p>