One of the problems often encountered in daily life is waiting lines in service systems. A long waiting line in a service system usually leads to customers leaving the system, resulting in losses for the service provider. The general clinic of Green Care is one of the clinics with a First Come First Served service discipline and a limited service capacity of 30 patient. The clinic often experiences patient congestion while waiting for service, which causes some patient to renege due to the long waiting time. This study discusses the service system at the Green Care General Clinic, considering impatient customers, specifically those who renege while waiting for service. The study was conducted by collecting data on arrival time, service time, and cancellation time while waiting for service. Based on the test results, the service model used in the general clinic is M/M/1/N. The research findings show that the service system at the general clinic has a high system utilization rate (ρ=80,84%), indicating a need for additional service facilities. The service model becomes M/M/2/N with the system utilization rate being ρ=40,42%.