Objective: The paper explores the current status and problems regarding the integration of medical insurance payment scope in regions such as the Yangtze River Delta and Beijing-Tianjin-Hebei, providing evidence to optimize medical insurance policies and enhance the fairness and accessibility of healthcare security. Methods: Through policy review and field research, a comparative analysis was conducted on the integration status and implementation challenges of medical insurance payment scope for drugs, medical service items, and medical consumables in the two regions. Results: Systematic negotiation and adjustment regarding existing medical insurance payment scope (i.e., the "existing items") are still absent among provinces and cities. Due to strong local characteristics of ethnic medicine, Chinese herbal decoction pieces, and institutional preparations, unified inclusion criteria and regulatory approval processes are absent. Medical service items still face inconsistencies in classification across regions regarding coding, nomenclature, definition, pricing units, and price standards. Unified separate charging policies and procurement models for medical consumables remain inadequate. Regarding newly added items in the medical insurance payment scope (i.e., the "increment"), provinces and cities also lack synchronized progress. New additions of Chinese herbal decoction pieces, ethnic medicine, and institutional preparations lack regional negotiation mechanisms. Newly added medical service items still deviate from the unified national standards outlined in the national project guidelines. Conclusion: Significant disparities exist in the medical insurance payment scope between the two economically advanced regions. To advance integration of medical insurance payment scope, various regions should establish an authoritative regional coordination mechanism based on national top-level design, optimize adjustment rules for the National Reimbursement Drug List and enhance medical insurance fund pooling. Meanwhile, they should consider regional economic differences in policy implementation, and gradually establish reinsurance risk-sharing mechanisms and special fund pools—funded through central fiscal allocations and regional medical insurance fund contributions—to mitigate fund risks. Furthermore, while strengthening regional collaborative supervision of medical insurance funds, building an information-sharing platform, and improving the convenience of cross-regional medical expense settlement to promote integration of medical insurance payment scope.