The Social Security Organization, as the largest insurance fund in the country, covers more than half of the Iranian population. The Social Security Organization, as the largest insurance fund in the country, covers more than half of the Iranian population. The main financial resources of this organization come from insurance premiums received from employers. The process of insuring workers and sending lists and paying social security premiums is not immune to deviation, and one of its examples is insurance evasion, which consequently confronts the organization with a deficit of resources and failure to fulfill obligations to insured persons and pensioners on time, and has a negative impact on the social welfare of the country. The present research aims to identify various types of insurance evasion based on the Identifying Types of Insurance Evasion Based on the Analysis of Work Experiences of Workers and Employers and Its Effects on Social Welfare (Case Study: Social Security Organization, Branch 3 of Mashhad). This research is exploratory in nature, qualitative in approach, and applied in purpose. Additionally, this study is cross-sectional (2020-2021) and descriptive-explanatory. The research was conducted using thematic analysis and in- depth interviews with 28 workers and employers in Mashhad. As a result of the analysis and open coding of the data, the central phenomenon of "insurance evasion" was obtained. Among the main categories obtained in this study are "stereotypical and unprofessional behaviors as well as innovative and professional behaviors of employers affected by the laws" in the phenomenon of insurance evasion.