One of the first questions people ask after moving to Japan is how much health insurance actually costs. Because premiums depend on your employment type, income, and municipality, the bill can come as a surprise if you do not know how the system calculates it.
Every resident in Japan is legally required to hold public medical insurance. You will be enrolled in either Employees' Health Insurance (Shakai Hoken) or National Health Insurance (Kokumin Kenko Hoken).
1. Employees' Health Insurance (Shakai Hoken / 社会保険)
If you work full-time for a Japanese company (or part-time meeting statutory hours), your company enrols you in Shakai Hoken. This system covers both health insurance and Employees' Pension (Kousei Nenkin).
- How it is calculated: Premiums are based on your Standard Monthly Remuneration (標準報酬月額), which is your average gross salary (including base pay, overtime, and allowances) during April, May, and June.
- The 50/50 split: Your employer pays half the premium and you pay half. Your half is automatically deducted from your salary every month.
- Average cost: Health insurance premiums are roughly 9.8% to 10% of gross salary (varying slightly by prefecture), meaning your half is about 4.9% to 5.0%.
- Dependants: Non-working or low-income spouses and children can be added as insured dependants at no extra premium cost.
2. National Health Insurance (Kokumin Kenko Hoken / 国民健康保険)
If you are self-employed, a freelancer, a student, unemployed, or working for an employer that does not offer workplace insurance, you must enrol in Kokumin Kenko Hoken (NHI) at your local ward office within 14 days of arriving or leaving your previous job.
- How it is calculated: NHI premiums are determined by your local municipality using a formula based on your previous calendar year's taxable income in Japan plus a fixed per-capita fee (均等割) for each person in your household.
- No dependant discount: Unlike Shakai Hoken, NHI does not have free dependant coverage. Each household member adds to the total bill.
- Payment method: Bills arrive by post in 10 annual instalments (usually from June to March) or are auto-debited from your bank account.
The "Year 1 vs Year 2" trap for new expats
If you move to Japan mid-year, you have zero prior-year Japanese taxable income recorded at city hall. As a result, your National Health Insurance bill in your first year will be near the minimum base rate (often ¥2,000 to ¥4,000 per month depending on the ward).
Maximum premium caps
To prevent astronomical charges for high earners, both systems have statutory annual maximum caps set by law. For National Health Insurance, the maximum total annual premium ceiling (combining medical, elderly care, and support levies) is set each year by the Ministry of Health, Labour and Welfare (around ¥1,060,000 per year).
What you pay at the clinic (The 30% Co-pay)
Having public health insurance means you do not pay full price when visiting a doctor or hospital. For working-age residents (ages 6 to 69), the statutory co-payment is 30% of the total cost for consultations, treatments, surgeries, and prescribed medication.
For high medical expenses in a single month, your out-of-pocket costs are further capped by the High-Cost Medical Care Benefit (高額療養費).
Where to confirm this
- Ministry of Health, Labour and Welfare: National Health Insurance framework
- Japan Health Insurance Association (Kyokai Kenpo) premium rate tables
- Your municipal ward office / city hall National Health Insurance section
Guides are dated rather than undated: last reviewed 12 August 2026. This is an organisational aid, not legal or immigration advice — always confirm anything consequential with your ward office, the Immigration Services Agency, or a qualified professional.