BackgroundHemophilia, a high-cost disease, is the only rare disease covered by basic medical insurance in all province of China. However, very few studies have estimated the medical expenditure of patients with this rare disease Therefore, this study is aimed at evaluating the medical expenditure of patients with hemophilia and identifying its determinants.MethodsThe study population included 450 patients with hemophilia who were extracted from the national insurance database between 2014 and 2016. An independent-sample Kolmogorov–Smirnov test was performed to compare the medical expenditure of patients with hemophilia covered under urban employee basic medical insurance (UEBMI) and urban residence basic medical insurance (URBMI). Quantile regression analysis was conducted to explore the factors that affect the medical expenditure of patients with hemophilia.ResultsThe total annual medical expenditure of patients with hemophilia in 2013, 2014, and 2015 had median of ¥7167 (US$ 1156), ¥3522 (US$ 577), and ¥4197 (US$ 677), respectively. The median medical expenditures of patients with hemophilia covered by UEBMI were ¥10,991 (US$ 1773), ¥2301 (US$ 377) and ¥8074 (US$ 1302), those of patients covered by URBMI were ¥4000 (US$ 645), ¥5717 (US$ 937) and ¥3141 (US$ 507) from 2013 to 2015. The differences in the medical expenditure of patients with hemophilia between UEBMI and URBMI from 2013 to 2015 were statistically significant. The number of admissions and the number of hospital days were statistically significant and positive for all quantiles. The types of medical service were statistically significant and negative for 50th quantile, and the reimbursement ratio was statistically significant and positive for 50th and 75th quantiles. (p < 0.05).ConclusionThe medical expenditure of patients with hemophilia was lower than that of patients with other common rare diseases that were not included in the scope of basic medical insurance reimbursement. It was also observed that the medical expenditure was mainly influenced by the severity of disease, and partly affected by the reimbursement rate.