Does Indemnity Private Insurance Increase Healthcare Utilization? Evidence from Korea's National Health Insurance System.

Purpose: South Korea's healthcare system is based on the National Health Insurance (NHI), and private insurance is commonly purchased to cover services not fully reimbursed by the NHI. Rising medical expenditures associated with indemnity-type private health insurance have become a growing policy concern. Patients and Methods: In this cross-sectional study, adults aged <65 years without chronic diseases were selected from the Korea Health Panel Survey (2019-2020). Participants were classified into fixed-benefit or indemnity private insurance groups. Healthcare utilization and expenditures were compared, and multivariable regression models were used to evaluate factors associated with medical use and visit frequency. Results: A total of 3,320 participants were included in the analysis. The indemnity group showed higher outpatient care use than the fixed-benefit group, with mean outpatient visits of 9.14 versus 7.46 per year. There were no significant differences in expenditures for emergency or inpatient services. In the multivariable analysis, indemnity insurance was associated with higher outpatient care use (adjusted OR, 1.503; 95% CI, 1.232-1.834) and a higher number of outpatient visits (adjusted IRR, 1.167; 95% CI, 1.069-1.274). Conclusion: These findings suggest that indemnity-type private insurance is associated mainly with greater outpatient healthcare utilization and outpatient expenditures among adults without chronic diseases. The findings should be interpreted as outpatient-focused associations rather than evidence of broader system-wide cost effects.