This paper explores how a new French law incorporating a new conceptualization of disability formulated at the international level by the WHO is appropriated at the local level by multidisciplinary teams of professionals in charge of the assessment of disability. Drawing on social representations theory, its concept of cognitive polyphasia and its conceptualization of legal innovation, the paper specifically examines how the teams deal with the tensions between the old and the new models of disability and how the group dynamic is associated with how they do this: by hybridization of old and new models, by selective prevalence according to context, or by displacement of one model. Focus groups with the teams (n = 65 from 10 groups), analysed with indicators of interaction, bring evidence of the three forms. They show how different groups, by drawing differently, depending on their relational dynamics, from a variety of meaning systems circulating at the cultural level, reach different decisions that may lead to different practices in the local implementation of the same laws. We finish by discussing how social representations theory, linking the cultural/global and the interactional/local levels, can enhance our understanding of how socio-psychological processes intervening in the appropriation of legal innovations may produce different practical implementations of the same new laws.