This study examines the effects of migration on medical expenditures among middle-aged and older people using data from the 2018 China Health and Retirement Longitudinal Study.The study revealed that middle-aged and older migrants had lower medical expenditures for both outpatient and inpatient care when their medical insurance coverage location differed from their residential location.This discrepancy is apparent not only in overall medical expenses but also in out-of-pocket costs after reimbursement.However,middle-aged and older migrants who received outpatient treatment in the previous month and inpatient treatment in the previous year tended to pay more for medical procedures.Mechanistic analysis indicated lower healthcare utilization and reimbursement rates among middle-aged and older migrants.Finally,this paper proposes policy recommendations,including the promotion of direct settlements of cross-provincial medical bills,the establishment of a nationally coordinated medical insurance system,strengthened health services for middle-aged and older migrants,and improved levels of health governance.