The article proposes an approach to studying and assessing the influence of factors on the volume of interbudgetary transfers income to municipal budgets. The relevance of the work is predetermined by the need to find ways to increase the replenishment of municipal budgets through the means of influence available for municipalities in order to fulfill their obligations and further territorial progress, including due to the unstable economic situation. Municipalities in Russia are in conditions of high dependence on incomes from higher-level budgets due to limited opportunities to strengthen their own revenue base, needing to attract as much gratuitous revenue as possible to their budgets. However, the aspects that have the greatest impact on the growth of intergovernmental transfers to the budget change over time and require elaboration. The aim of the work is to identify influencing factors that have a positive effect on increasing the incomes of interbudgetary transfers to municipal budgets, as well as to establish the degree of their influence on the volume of financial assistance provided. The study was carried out using industry-wide methods of system analysis with using statistical tools; the objects of the study were municipalities of the Samara region. The revenues of municipal budgets were analyzed, including to identify emerging trends. In addition, an assessment of factors and the degree of their influence on increasing the revenue base of municipalities in terms of gratuitous revenues from the subfederal level was carried out on the basis of correlation and regression analysis, including a dynamic comparison of the calculated models based on the results of 2012 and 2022. The key factors that have the greatest impact on the replenishment of municipal budgets through interbudgetary transfers have been identified, which has become an element of work’s scientific novelty. The results of the study can be used in the development of municipal policy in the field of interbudgetary relations, as well as become the basis for further study on a national scale.