national health insurance
Refers to Japan's public health insurance system for self-employed, unemployed, and retired individuals; often abbreviated as 国保 (こくほ).
Self-employed people need to enroll in national health insurance.
National health insurance premiums are calculated based on the previous year's income.
Since I became self-employed, I enrolled in national health insurance.
I have to pay my national health insurance premiums every month.
I showed my national health insurance card at the hospital.
健康保険 usually refers to the employees' health insurance provided through a company, while 国民健康保険 is the separate scheme for self-employed people, retirees, and others not covered by an employer plan.
社会保険 broadly covers employee-based public insurance, whereas 国民健康保険 is the specific health insurance scheme for the self-employed and others outside employee coverage.