Objective:To construct and validate a theoretical model of residents′ willingness to participate in tiered medical care based on harmonious management theory, providing reference for promoting the tiered medical care system and aiding governmental decision-making.Methods:Based on the harmonious management theory and literature review, a model capturing residents′ propensity to engage in tiered medical care was formulated. Using convenience sampling method, a questionnaire survey was conducted on 2 067 residents from 24 communities in Zhejiang province from April to May 2022. Descriptive statistical analysis was conducted on the survey results, and multilevel linear regression and structural equation modeling were used to analyze the driving mechanism of residents′ willingness to participate in tiered medical care.Results:The willingness rate of residents to participate in tiered medical care was 69.7%, which was at an average level. Regression insights highlighted the positive influence of policy support perception ( β=0.170, P<0.01), awareness of management mechanisms ( β=0.093, P<0.01), cognitive attitudes ( β=0.102, P<0.01), and trust levels ( β=0.244, P<0.01) on residents′ participation willingness. In contrast, resource allocation perceptions lacked a significant effect ( β=0.065, P>0.05). The structural equation model revealed that cognitive attitudes played a mediating role in the " policy system perception → participation willingness" and " management mechanism perception → participation willingness" pathways, with effect sizes of 0.030 and 0.039, respectively. Trust levels also mediated these paths, with effect sizes of 0.039 and 0.045, and entirely mediated the " resource allocation perception → participation willingness" path, registering an effect size of 0.053. Conclusions:The harmonious management theory can be used to explain the formation mechanism of residents′ willingness to participate in tiered medical care. The government and medical institutions urgently need to further improve residents′ awareness of tiered medical care, focus on enhancing residents′ trust, and further improve policies and management measures such as financial investment, medical insurance reimbursement, and referral systems.