To evaluate the impact of Regorafenib in the third-line treatment of patients with metastatic colorectal cancer (mCRC) on the insurance budget when incorporated in the reimbursement list. Building a budget impact model to assess the impact of Stivarga on health insurance expenditure over three years after the inclusion of Regorafenib in China's national reimbursement drug list (NRDL). In the model, the disease incidence data were abstracted from literatures, disease diagnosis rate, treatment rate and direct medical costs were obtained from an expert opinion survey. Other data such as market share of third-line treatments were derived from market research. Total annual reimbursement expenditure in 1, 2, and 3 years following the NRDL inclusion was decreased by 90 million RMB, 67 million RMB and 47 million RMB respectively. The cost reduction is mainly due to the potential elimination of the current non evidence-based salvage therapies. Sensitivity analysis was carried out on the parameters of monthly treatment cost, market shares and reimbursement ratio. The sensitivity analysis did not change the direction of the results indicating that the basic analysis results are robust. The analysis estimated that, following the inclusion of Regorafenib in China's NRDL for third-line treatment of patients with metastatic colorectal cancer (mCRC), the overall health care expenditures were reduced due to the potential elimination of the current non evidence-based salvage therapies.