The relevance of foreign language proficiency of university graduates led to the design and pilot study of the of non-linguistic students' language mediation development model. This model was implicated at the MGIMO of the Ministry of Foreign Affairs of Russia, the Odintsovo branch (Moscow Region) in the I-IV courses, Plekhanov University of Economics and the Kuzbass Institute of the Federal Penal Service of Russia (Novokuznetsk, Kemerovo region, in the I-II courses) in 2019-2021. The authors have disclosed the components of the model based on a set of cultural, competence and communicative approaches. Besides, mediation training methods and amendments to the content of language education were presented here. The working concepts of the study are specified: types of mediation (interactive, non-interactive and hybrid), approaches and methods of developing mediation skills. The principles of selecting the content of language education (development and development of practice-, cultural and professionally-oriented variable topics; priority of dialogical forms of communication in the language in the field of the studied concept with an emphasis on mediation; conducting negotiations in the language, etc.) based on the results of mediation are substantiated. The pilot study highlighted that the content of education and teaching methods were the most flexible components of the designed model, that were quite easily transformed into any type of training (standard, mixed, hybrid and/or distance). The analysis of the language teaching methods used (debates, case studies, etc.) proved their compliance with the requirements of the current standard. The presented results of the pilot study, under the implementation of the developed model, including the period during the COVID-19 pandemic, verified by the data of control and pilot groups and measurement procedures, proved the effectiveness of the nonlinguistic students' language mediation development model.