Income inequality is a significant social problem that differentiates society according to the amount of income into structured groups, which do not always objectively correspond to the generally required national economic or political idea of income equality in society. The high level of income inequality, including its inappropriate structure, is a source of intergroup tension, hinders balanced economic development and limits the development of society as a whole with reference to social disadvantage and income stratification of society. The contribution aims to present social income as an indicator for moderating the income inequality in the society through which the subjects of social policy may influence the distribution of money income among the individual social groups within the society and thus improve the living standard of the population in the given country. The level of influence of income inequality through social income will be expressed by the so-called income inequality gap and will be assessed by means of changes in the index of income inequalities on the case of the Czech Republic.