Objective   To analyze differences in catastrophic health expenditure (CHE) between urban and rural elderly people and their associates in China to provide a reference for reducing CHE and urban-rural health care inequalities.

  Methods  From the Chinese Longitudinal Healthy Longevity Survey (CLHLS) conducted in 2018, we extracted the data on health expenditures among 7 196 urban and rural residents aged ≥ 60 years in 23 provinces/municipalities/autonomous regions across China. Oaxaca-Blinder decomposition was used to analyze urban-rural disparity in CHE among the elderly.

  Results   Among the 7 196 elderly, 830 (11.53%) reported CHE and the proportion of the elderly with CHE was significantly lower among the urban elderly than that among the rural elderly (9.85% vs. 13.93%, χ² = 28.443, P < 0.001). The results of unconditional multivariate logistic regression analysis showed that having chronic diseases, with fair or poor or very poor self-rated health, and having poor or very poor self-rated household economic status were risk factors for CHE among the elderly; while, with the education of 7 years and above, living in urban areas and having medical insurance were protective factors for CHE. The results of Oaxaca-Blinder decomposition analysis revealed that the proportions of explainable and unexplainable part of the difference in CHE between urban and rural elderly were 26.83% and 73.17%, respectively. Of the explainable partial difference, 19.51% were attributed to years of education (β = 0.008, P = 0.002), 14.63% to suffering from chronic diseases (β = – 0.006, P < 0.001), 17.07% to self-assessed economic status (β = 0.007, P < 0.001), and 4.88% to participation in health insurance (β = – 0.002, P = 0.006); 41.46% of the unexplained partial difference were attributed to gender (β = – 0.017, P = 0.048) and 43.90% to the presence or absence of pension insurance (β = 0.018, P = 0.015).

  Conclusion  Urban-rural inequalities in catastrophic health expenditures exist among elderly residents in China and the inequalities may be mainly attributed to gender, years of education, suffering from chronic diseases, self-assessed economic status, participation in pension insurance, and the presence of medical insurance.