Social security is one level, two levels and three levels.

Legal analysis: the concepts of social security category I, II and III are different in different regions. Take Shenzhen as an example: the medical insurance for enterprise employees in Shenzhen is divided into three grades: basic medical care, basic medical care and basic medical care. The payment, treatment and adaptation population are different. Social insurance refers to the system that the state establishes a social insurance fund through legislation to give necessary material help to workers who participate in labor relations when they lose their ability to work or are unemployed. Social insurance is not for profit. The main items of social insurance include endowment insurance, medical insurance, unemployment insurance, industrial injury insurance and maternity insurance. The state establishes social insurance systems such as basic old-age insurance, basic medical insurance, industrial injury insurance, unemployment insurance and maternity insurance to protect citizens' right to get material help from the state and society according to law in cases of old age, illness, industrial injury, unemployment and maternity.

Legal basis: Article 2 of the Social Insurance Law of People's Republic of China (PRC) The state establishes social insurance systems such as basic old-age insurance, basic medical insurance, industrial injury insurance, unemployment insurance, maternity insurance, etc., to protect citizens' right to get material help from the state and society according to law in case of old age, illness, industrial injury, unemployment and maternity.