This article discusses the theoretical and methodological aspects of the manifestation of ethnicity and of its institutionalization in the regional identity policy of Russian republics. The author analyzes how ethnicity is included in politics. Indicators are identified that indicate the expression of ethnicity in identity politics. Identity policies as policies promoted by state actors are regarded as systemic and aimed at institutionalizing ethnic categories thus helping create and sustain a sense of “Us – Them” and form subjective assessments towards such categories. The use of socio-constructivist methodology leads us to the conclusion that identification and institutionalization are related processes that occur simultaneously and mutually reinforce each other. The institutionalization of ethnicity is manifested in the rooting of ethnic categories in the political process of the republics and their role of maintaining or changing the regional institutional order. Building on this assumption, the author proposes an analytical model based on the allocation of three levels of the process of ethnicity institutionalization in identity politics: the normative, the narrative-mythological, and the symbolic level. The normative level includes the establishment of ethnic categories in the political nstitutions of the region and is manifested in the normative consolidation of ethnic discourse, i.e. in normative documents, in the distribution of power positions, in language policies expressing ethnic preferences etc. The narrativemythological level determines the significance of ethnic markers in the discourse of regional historical memory and myth-making. The symbolic level is defined as the incorporation of ethnicity into the symbolic attributes of the region. A set of indicators can be used to operationalize this three-level model in empirical studies of ethnicity institutionalization in Russian republics.