["The International Journal of Health Planning and Management, EarlyView. ", "\nABSTRACT\nUnder localised administrative frameworks, migrants usually face obstacles in obtaining necessary public services. To enhance the accessibility and convenience of health insurance reimbursement, China introduced immediate reimbursement for trans‐provincial inpatient care in 2017. Using data on 10,614 individuals from the China Migrants Dynamic Survey and administrative records from 287 cities, this study employed prosperity score matching and instrumental variable methods to assess the policy's health effects on middle‐aged and older migrants. Results revealed a significant positive association between health status and the number of hospitals offering immediate reimbursement (P < 0.01). Mechanism analysis showed no change in social integration, but higher reimbursement convenience increased health insurance participation (P < 0.01) and timely healthcare utilisation (P < 0.05) among this population, but these effects were limited to tertiary hospitals. The study demonstrates that reimbursement convenience improves health outcomes for this group, highlighting the need for more accessible insurance schemes for vulnerable populations.\n"]