OBJECTIVE： To evaluate the economics of the full coverage policy for hypoglycemic essential medicines in Taizhou city， and to provide reference for improving medicine accessibility and essential medicine system in China. METHODS： The electronic health records and financial input data of diabetic patients were extracted from different districts and counties of Taizhou city during 2009-2016. In cohort study design， taking the implementation time of each district and county’s policies as the breakpoint， the data recorded annually were processed as annual data， forming the cohort data for 1 year before （baseline year） and 3 years after the implementation of the policies. According to the choice of free medicines after the implementation of the policy， they were divided into policy group and control group. Propensity score matching was used to balance the differences between two groups to get the final sample， and then the economics of the policy was evaluated with the methods of difference-in-differences. The cost and benefit of implementation policy were calculated. RESULTS： Totally 14 744 people of each group were got by propensity score matching. The mean annual financial expenses on free medicine per capita were 263.8 yuan. Compared with baseline year， mean annual medicine expenses per capita reduced by the policy were 649.2 yuan， and mean annual hospitalization expenses per capita were 624.7 yuan. Thus the input-output ratio of the policy was 1 ∶ 4.8. CONCLUSIONS： The implementation of the policy is beneficial to reduce the cost burden of patients and economical. It can be popularized and sustained through scientific design combined with relevant policies.