Income inequality is an important obstacle to the growth and expansion of social welfare. Developed societies use various tools to overcome this problem. The social security system is one of the most well-known of these tools. In this study, the effect of social security costs on the convergence of income distribution in the provinces of the country in the period 1397-1387 has been investigated. In this research, the subject has been studied through spatial methodology. The results showed that the long-term costs of social security have a significant negative effect on the convergence of income distribution in the provinces, but short-term costs have no effect. Absolute and conditional convergence coefficient shows that the provinces of the country converge to a level of income distribution in the long run. The estimated convergence velocity is 0.061 in the absolute convergence state and 0.075 in the conditional state. The findings also showed that inflation and human capital have a positive and significant effect and Internet penetration has a negative and significant effect on the convergence of income distribution. Kuznets hypothesis was confirmed in the provinces. The study of the effects of overflows in 1397 showed that the long-term costs of social security in one province affect the neighboring provinces and Isfahan province due to its proximity to 9 provinces has been able to have the greatest effect of overflows on other provinces.