Since the introduction of National Health Insurance(NHI) in 1977, it has grown rapidly and contributed to extendpatientʼs access to the health care services. However, limited coverage for health care services of NHI has beenongoing challenge and private health insurance(PHI) has been rising as an alternative source of enhancing coverageand saving out-of-pocket(OOP) expenditure for patients. In this study, after controlling for socio-demographic,economic, health related variables, we identified the patientsʼ healthcare utilization and subsequent OOP expendituredepending on their PHI enrollment and their enrollment types(fixed benefit, indemnity, fixed benefit plus indemnity). Data were collected from the 2010 Korean Health Panel. The unit of analysis was a member of household(n=13,324). Of the 13,324 cases, 70.7% of patients held PHI, in detail, fixed benefit(47.0%), indemnity(3.6%), fixed benefit plusindemnity(20.1%). Major findings showd that patients who enrolled in PHI used more outpatient services(outpatientvisit, number of physician visit, number of examination) and spent more OOP expenditure than non-PHI patients. There were also differences of healthcare utilization and OOP expenditure among the types of PHI. In addition, PHIpatients used more inpatient services(inpatient use, number of hospitalization, LOS), but there was no significantdifference between PHI and non-PHI patients with regard to the OOP expenditure. Thus, we could not find anydistinct relationship between the types of PHI and patientsʼ tertiary hospital use. Policy-makers should need carefulpolitical deliberation for monitoring the effect of PHI on health care utilization and subsequent expenditure not only toimprove patientsʼ coverage but also to save their OOP expenditures.