Post-payment for patients can minimize their errands and improve their medical experience. Since February 2019, Hangzhou Municipal Health Commission began to try the " post-payment" service. This mode is integrated into the municipal credit system, and the patients can obtain the corresponding credit line according to their credit rating. Within such line, the patient can pay only once for all their medical services received per visit. The mode covers all Hangzhou residents with credit rating and has served nearly 20 million outpatient and emergency patients with expedient services. Thanks to the reform, the number of payment for patients to see a doctor reduced from an average of 2 to 3 times to only 1 time. It is proved that the credit system can realize payment after medical service and it is controllable.