The digital transformation leads to changing work contexts and new work objects that give rise to the necessity of collaboration across occupational boundaries. Yet there is a lack of theoretical models of cross-occupational collaboration, particularly with regard to individuals’ cross-occupational collaboration competency (COCC). In order to close this research gap, this article presents a theoretical model of COCC and associated indicators which can be subject to education and diagnostics in VET. In accordance with activity theory, cross-occupational collaboration is characterized as an activity system. While an activity is collective in nature, its role-constituting elements (e.g., division of labor) point to role-theoretical approaches. This paper reviews role-theoretical frameworks and applies structural symbolic interactionism as a framework for modeling an individual’s COCC. Using its conceptual apparatus, a hierarchical model of an individual’s capacity for cross-occupational collaboration within an activity system is developed. Its elements are (i) knowledge about one’s own occupational role, (ii) knowledge about the roles of the cooperation partners with other occupations, (iii) latent role distance, (iv) role-taking, and (v) object-oriented role coordination/role-making. This model can also be used as a basis for assessments that may lead to empirical investigations of how to promote individuals’ COCC.