This study aims to understand the difference in trauma patients' use of health services in Korea according to insurance type and the Injury Severity Score. Andersen's behavioral model of health service use is employed to identify the factors influencing their use. Claims data from January 1 to December 31, 2016 were extracted from both the Health Insurance Review and Assessment Service and the automobile insurance screening center for all the medical treatments identified with the Korean Triage and Acuity Scale and Injury Severity Score. Using the Health Insurance Review and Assessment Service's remote statistical analysis system, hierarchical regression and negative binomial analyses were conducted to determine the effect of predisposing, enabling, and need factors on health service use. The results demonstrate that the use of Korean health services is relatively equitable since medical expenses for trauma patients are greatly influenced by need factors. However, the length of time trauma patients stay in the hospital appears to differ according to insurance type. This study suggests that healthcare policies need to increase coverage benefits and improve medical billing for patients with severe trauma, as well as develop a more robust screening system for patients with mild to moderate impairments.