Abstract Background Insurance reimbursement provisions in South Korea limit osteoporosis medication availability for patients with T-scores exceeding − 2.5. This study aimed to evaluate the financial impact and fracture prevention of continuous denosumab therapy until a T-score>-2.0 (Dmab-C strategy), versus discontinuation of denosumab after reaching T-score>-2.5 (Dmab-D strategy) in osteoporosis patients. Methods A cost-consequence analysis from a Korean healthcare system perspective was performed using a newly developed Markov model. The incidence of vertebral and non-vertebral fracture, fracture-related deaths, drug costs, and fracture-treatment costs were estimated and compared between Dmab-C and Dmab-D strategy over a lifetime in eligible patients aged 55 years. Results Base-case analysis revealed that Dmab-C prevented 32.21 vertebral fracture (VF) and 12.43 non-VF events per 100 patients over a lifetime, while reducing 1.29 fracture-related deaths. Lifetime direct healthcare cost saving per patient was KRW 1,354,655 if Dmab-C replaces Dmab-D. When productivity losses were considered, Dmab-C saved KRW 29,025,949 per patient compared to Dmab-D. The additional treatment costs of Dmab-C could be offset by the higher subsequent treatment costs and fracture treatment costs of Dmab-D. The sensitivity analysis showed consistent patterns with results of the base-case analysis. Conclusion Continuous treatment using denosumab until osteoporosis patients achieve and maintain a T-score of -2.0 would provide greater clinical and economic benefits in terms of fracture prevention and reduced mortality risks compared to outcomes from discontinuing treatment at a T-score of -2.5 or above. This new treatment strategy would effectively lower the risk of fractures and fracture-related mortality, ultimately leading to lower medical expenses.