Due to serious illness, high expenses are reimbursed. Serious illness insurance is to reimburse the high medical expenses incurred by urban and rural residents due to serious illness. The purpose is to solve the problem of "poverty caused by illness and returning to poverty due to illness", so that most people will not fall into economic difficulties because of illness. Serious illness medical insurance for urban residents is an auxiliary insurance established on the basis of basic medical insurance for urban residents. It is used to solve the problem that the medical expenses accumulated by insured residents after hospitalization (including prescribed outpatient chronic diseases) are paid by the basic medical insurance fund for urban residents according to regulations and exceed the deductible line of serious illness insurance.