🏥 Japan Health Insurance Rate by Prefecture
Look up Japan Health Insurance Association (協会けんぽ) premium rates for all 47 prefectures and estimate your monthly health insurance premium from your standard monthly remuneration.
What is this tool?
For most company employees in Japan, health insurance is provided by the Japan Health Insurance Association (全国健康保険協会, Kyōkai Kenpō) — often called 協会けんぽ. Unlike National Health Insurance, which is local, 協会けんぽ sets a single premium rate for each prefecture (roughly 9.6%–10.8% combined), applied to your 標準報酬月額 (standard monthly remuneration). The total is split equally between employee and employer. On top of the medical rate, anyone aged 40–64 also pays a 介護保険 (long-term care) portion — about 1.905% combined — because they are the 第2号 insured for care. Rates are revised every September and differ by prefecture because each local 協会けんぽ branch sets its own scale. This tool lets you pick any of the 47 prefectures, enter your standard remuneration, and see the combined rate, both shares, and the estimated monthly premium. For the local (municipal) alternative see the NHI premium tool, and for the pension side see the employees' pension tool.How it works
The medical premium rate is looked up by prefecture (a representative 協会けんぽ general rate, per mille). For ages 40–64 a 介護 (care) portion of about 1.905% combined is added. The total rate is multiplied by the standard monthly remuneration and split equally between employee and employer.
| Element | Basis | Notes | --- | --- | --- | Medical rate | by prefecture | ~9.6–10.8% combined | Care portion (40–64) | added | ~1.905% combined | Split | equal | employee / employer ½ each |
|---|
Kyokai Kenpo (匿会けんゑ) premium components (FY2026, applied from March 2026) Kenpo health rates are set per prefectural chapter; the 1.62% care rate is uniform nationwide and applies only to members aged 40–64.
| Component | Rate (FY2026) | Paid by |
|---|---|---|
| Health insurance (medical), national average | 9.9% (prefecture range ≈ 9.4%–10.1%) | Employee ½ / Employer ½ |
| Long-term care (age 40–64 only) | 1.62% (nationwide uniform) | Employee ½ / Employer ½ |
| Standard remuneration ceiling (Grade 50) | ¥1,390,000 / month | — |
How to use
- Select your prefecture from the 47 options.
- Enter your standard monthly remuneration (標準報酬月額) in 万円.
- Choose your age bracket (under 40, or 40–64 with the care portion).
- Click Calculate to see the rate, both shares, and estimated monthly premium.
Frequently Asked Questions
Why do health insurance rates differ by prefecture?
協会けんぽ sets rates at the prefecture (branch) level based on each region's medical cost experience, so the combined rate ranges from about 9.6% to 10.8% across Japan's 47 prefectures.
What is the 介護 (care) portion?
For insured people aged 40–64, a long-term care insurance portion of about 1.905% combined is added to the medical rate, because they are the 第2号 insured for care insurance. It disappears at 65 when care moves to the municipal system.
How is the premium split?
The total combined rate (medical + care) is split exactly in half — the employee pays half (deducted from salary) and the employer pays half.
Does this apply to union health plans (組合健保)?
No. This tool models 協会けんぽ (the association plan for most small/medium employers). Company 健康保険組合 plans set their own rates, which may be higher or lower.
When do rates change?
協会けんぽ revises prefecture rates every September. A change mid-year is normal and reflects updated regional medical costs.
This tool is for informational purposes only and does not constitute financial advice. Consult a qualified financial professional for advice specific to your situation.
Tips & Advice
Your 協会けんぽ rate is set at the prefecture level, not by your company, so colleagues in different prefectures pay different rates even for the same salary. The rate resets every September, so a mid-year change is normal. Because the care portion only applies to ages 40–64, your health premium drops noticeably at 65 when care insurance moves to the municipal 第1号 system. The premium is pre-tax for the employee share. If your employer is small and not in 協会けんぽ, you may instead be in a 健康保険組合 (union plan) with its own rate — check your payslip. Combine this with our employees' pension tool to total your statutory payroll insurance deductions.
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Sources & References
Last reviewed: August 2026.
- National Health Insurance Association (Kyokai Kenpo) — Kyokai Kenpo — insurance rate table.
- National Health Insurance Association (Kyokai Kenpo) — National Health Insurance Association (Kyokai Kenpo).
Limitations
Disclaimer: This tool uses representative 協会けんぽ general rates per prefecture and a standard 1.905% care portion. Actual rates are published by 協会けんぽ each September and vary by branch and plan. It is not official insurance advice — confirm the current rate with 協会けんぽ or your payroll office.