Despite the improved living standards in South Korea, people with disabilities still experience health disparities. Therefore, we analyzed differences in mortality rates among people with disabilities according to income level and residential area using representative data from the National Health Insurance Service in South Korea. Descriptive statistics and Cox proportional risk models were used to identify the risk factors for mortality affecting people with disabilities stratified by income level and residential area. Those living in non-metropolitan areas and low-income households had high mortality risks, suggesting that income level and residential area were related to mortality risk. The mortality risk of those with a high-income level was 1.534 times higher in non-metropolitan areas than in Seoul metropolitan areas (95% confidence interval [CI] = 1.44–1.63). Among people with low income living in non-metropolitan areas, the crude hazard ratios of mortality risk were 1.26 (95% CI = 1.14–1.39), 1.44 (95% CI = 1.34–1.54), and 1.39 (95% CI = 1.20–1.61) for those with brain lesions, sensory impairment (visual/hearing/speech impairment), and kidney failure, respectively. No significant differences were observed between people with autism in non-metropolitan and Seoul metropolitan areas and those with low- and high-income levels. Health issues and countermeasures are crucial to reduce mortality risk among people with disabilities.