OBJECTIVE Diabetes mellitus (DM) prevalence has been rapidly increasing in Taiwan and globally. Team care for DM has been provided through diabetes shared-care networks in Taiwan more than 20 years. METHODS The study analyzed the National Health Insurance (NHI) claims data from 2005 to 2014 to better understand diabetes care accountability and utilization in Taiwan. RESULTS The completion rate of annual check-ups for various metabolic measurements increased significantly, which indicates improvement in diabetes management quality. The average annual visits and drug cost for each patient increased enormously from 2005 to 2014. The annual number of outpatient department/inpatient department (OPD/IPD) patients with diabetes undergoing dialysis increased. The number of OPD visits in patients with diabetes was 1.9 times higher than that in all patients in general. IPD cost appeared to increase, whereas both drug cost and the average length of hospitalization per patient decreased. Endocrine and metabolic diseases were still the leading cause of OPD expenses. The leading cause of IPD expenses was respiratory diseases. An increasing trend was noted in the medical cost for patients with microvascular instead of macrovascular complications. OPD care for patients with diabetes was rather evenly distributed since 2009. Regarding IPD care, medical centers and regional hospitals each hospitalized 37% of the diabetic outpatients in 2014. CONCLUSIONS Accountability of diabetes care in Taiwan improved significantly till 2014. The ongoing fight against DM and tracing, examining and learning from the overall outcomes in future decades is still required.