Fiscal decentralization at the local level is aimed at ensuring financial autonomy to strengthen the role of local self-government bodies. In fiscal decentralization, it is also important to clarify what powers are given to local governments so that they can determine their spending priorities and have some capacity to expand local revenue sources. The administrative-territorial reforms of RA, in particular, the enlargement of communities, is a new challenge from the point of view of the development and independence of the local self-government system of RA, but to have a well-established local self-government system, it is very important to increase both the absolute and relative indicators of the communities' incomes. The results of the analysis carried out in the communities of Armenia for 10 years show that the communities have a trend of steady growth of their incomes, which, however, is not always accompanied by an increase in the share of their incomes in the total incomes. The latter is because, despite the RA administrative-territorial reforms, the communities continue to be significantly dependent on the state budget. With the emphasis on the importance of assessing the impact of enlargement in communities after the RA administrative-territorial reforms, there is a need to introduce a methodology for calculating several indicators of fiscal decentralization in communities, which will take into account not only indicators at the local level but also other macroeconomic indicators characterizing the country's economic situation, such as GDP.