Purpose: Non-essential hospitalization day of inpatient diabetes threatens health seriously and contributes to great economic burden on individuals and the society. Studying the essential utilization of hospitalization services is conducive to the reduction in the burden of diabetes. The purpose of this study is to identify the existence of non-essential hospitalization days during hospitalization in diabetic patients through exploring the use of health care in different types of insured patients. Patients and methods: A sample of 6731 admission records from 5929 hospitalized patients was studied. Binary logistic regression was performed to estimate the adjusted effects of health insurance status on readmission. Multiple stepwise linear regression was performed to estimate the adjusted effects of health insurance status on length of stay (LOS), direct medical expenses (DME), out-of-pocket (OOP) expenditures, and percentage of individual payment after reimbursement (PIPAR). Adjusted odds ratios (with 95% CI) were reported as the results of logistic regression models and linear regression models, respectively. Results: Adjusted 7-day readmission rate and 30-day readmission rate were not significantly different between urban and rural resident basic medical insurance (URRBMI) and urban employee basic medical insurance (UEBMI). Compared with inpatients under URRBMI, the adjusted LOS and DME were significantly higher for UEBMI inpatients (adjusted OR of 2.6, 95% CI=1.9-3.2, adjusted OR of 1870.85, 95% CI=1370.97-2370.73, respectively). Adjusted OOP and PIPAR were significantly lower for UEBMI inpatients (adjusted OR of-970.86, 95% CI =−1111.63-−830.10, adjusted OR of −0.19, 95% CI=−0.20-−0.18, respectively). Conclusion: There was a non-essential hospitalization day existing in the treatment of diabetes. Moral hazard has been found in UEBMI which would trigger overtreatment in hospitalization of diabetics, and the lower PIPAR of UEBMI was one of the main causes of moral hazard.