目的：医疗保障是减轻群众就医负担、增进民生福祉、维护社会和谐稳定的重大制度安排。本文旨在从理论与实际层面解析城乡居民基本医疗保险“断保”行为的影响机制与治理路径,为巩固全民参保成果提供学理依据。方法：本研究以重庆市M镇为样本,通过实地访谈当地医保部门负责人、村委会工作人员和农村居民,构建了涵盖理想化政策、执行主体、目标群体和执行环境的四维分析框架。结果：城乡居民“断保”行为与医保动员宣传不足、农村居民经济压力大、个体认知偏差以及非正式文化环境制约等因素存在关联。结论：建议从推进参保立法、优化筹资机制、增强制度包容性、提升医保公共服务及深化政策认知等方面系统施策,以驱动城乡居民形成稳定、可持续的参保秩序。

Objective: Healthcare security is a major institutional arrangement to reduce the burden of medical treatment on the public, enhance people’s well-being, and maintain social harmony and stability. This article aims to analyze the impact mechanism and governance path of the "discontinuation of basic medical insurance" for urban and rural residents from both theoretical and practical perspectives, providing a theoretical basis for consolidating the achievements of universal participation in basic medical insurance. Method: This study used M Town in Chongqing City as a sample and conducted on-site interviews with local directors of healthcare security administration, village committee staff, and rural residents to construct a four-dimension analysis framework covering idealized policies, implementation subjects, target groups, and implementation environments. Result: There is a correlation between the behavior of "discontinuation of insurance" among urban and rural residents and factors such as insufficient mobilization and publicity of medical insurance, high economic pressure on rural residents, individual cognitive biases, and informal cultural environment constraints. Conclusion: It is recommended to implement systematic measures in promoting insurance participation legislation, optimizing financing mechanisms, enhancing institutional inclusiveness, improving public medical insurance services, and deepening policy awareness to drive the formation of a stable and sustainable insurance order for urban and rural residents.