For health insurance policies, immediate reimbursement and later reimbursement can have different effects on people's total health care expenditures. Utilizing the establishment of the provincial online systems for settlement of intra-provincial medical bills, this paper constructs two instrument variables and implements a triple difference-in-difference model to identify the effect of reimbursement methods on health care expenditures. With a cross-sectional data set of migrants' inpatient expenditures and a panel data set of outpatient expenditures, the estimates indicate that immediate reimbursement significantly increases total inpatient expenditures by 78% and increases total outpatient expenditures by 128% on average.