In order to prove its authenticity. According to the inquiry of China Travel Service. Com, residents' medical insurance reimbursement needs to provide hospitalization invoices, hospitalization expenses details, diagnosis certificates, discharge summaries, medical records and other materials, and the hospital needs to stamp to prove its authenticity. The doctor's signature is an important basis to prove the patient's condition and treatment plan, which is helpful to ensure the fairness and rationality of medical insurance reimbursement.