Introduction. The relevance of the research undertaken is determined by the fact that the ambiguous VUCA world creates a changeable and complex environment of the modern educational system, in which there is an obvious gap between the needs of the digital economy and the content of school education, as a result of which new professional deficits of teachers arise, including subject ones. Purpose of the study is analysis and generalization of the results of the monitoring of professional issues of teachers in the field of subject competences (Russian language), manifested in the context of the digital transformation of education. Materials and methods. The main research methods are a survey of 1075 Russian language teachers from Belgorod, Volgograd, Lipetsk, Rostov, Krasnodar, Stavropol regions, including Chechen Republic (by Google-forms); method of scaling empirical data; interpretation method. Research results. Data were obtained on the different degrees of severity of professional deficits in Russian language teachers, which are manifested in the context of the digital transformation of education. There was a lack of awareness of teachers about the components of the methodological system (more than 50%) in the field of methodological competencies; on the means of individualization, differentiation of educational programs; on the principles of teaching the Russian language (over 60%). We state small deficits associated with ideas about meta and subject skills (more than 20%), about the structure of the Final State Examination (less than 20%). Problematic issue is knowledge in the field of theoretical foundations of the morphemic structure of a word, its word-formation capabilities (more than 70%) in the field of subject competences; transitional phenomena in the field of morphology (more than 60%), syntactic connections and relationships (more than 50%). The scientific novelty of the research is in fixing and stating whether teachers of the Russian language have professional issues (methodological and subject). The obtained results of the research can be used in the organization of a multilateral system of support for teaching staff in the subject area "Russian language".