Built on a stream of literature that has identified a lack of studies that examine the post-adoption behavior of information systems (IS) users, and especially, in relation to the usability of systems that support teaching and learning processes, this paper proposed an usability-extended Expectation-Confirmation Model (ECM) to determine the variables that impact users' continuance intention to use the system for acquisition and evaluation of digital competence (DC) – the CRISS platform. The model was tested using a cross-sectional survey instrument on 353 primary and secondary school teachers in six European countries who participated in the ongoing pilot project and used the CRISS platform. Findings provided solid support for theoretical relationships posited in the original ECM. Furthermore, the continuance intention of the CRISS platform in the model was directly driven by teachers’ levels of satisfaction, perceived usefulness and perceived efficiency, and indirectly through satisfaction by perceived effectiveness. However, the level of computer skill and duration of use, expressed in hours per week, did not moderate the satisfaction-continuance intention relationship.