This paper presents a participatory design-based research that aimed to create a model of co-creation in the curriculum in Technology-Enhanced Learning Environments (TELE) in tertiary education, specifically to co-design assessment between professors and students. This qualitative research followed four phases divided into five stages with two iterative cycles of design and re-design. Accordingly, a mixed method approach was used to collect the data: systematic literature review, semi-structured interviews, and student surveys. As a result, the model highlights and distinguishes four different dimensions: characterization, co-creation, reflection, and technology. The initial three dimensions are depicted in chronological order, while the fourth dimension is pervasive throughout all preceding stages. Furthermore, we depicted how technology is present throughout the co-creation process, delineating its role in each dimension distinctly. In conclusion, this model expands the basis of co-creation in the curriculum literature and provides tools for practitioners to innovate in their academic contexts, enabling student involvement in their own learning journey through co-creation. Further research in this field should be carried out, so we intend to apply this research to other fields of study and educational levels, contexts, and situations.