According to the social security network, the medical insurance fund for serious illness of urban and rural residents is the source of expenses for the insured to apply for reimbursement after suffering from serious illness. The medical insurance fund for serious illness of urban and rural residents consists of the basic medical insurance fund for urban residents and the new rural cooperative medical insurance fund, and a certain amount is set aside from these two funds as the serious illness insurance fund.

Serious illness insurance for urban and rural residents is an institutional arrangement to further protect the high medical expenses incurred by seriously ill patients on the basis of basic medical security, which can further amplify the effectiveness of the security, is the expansion and extension of the basic medical security system, and is a useful supplement to the basic medical security.