Health insurance
All residents of Japan are required to be covered by a health-insurance scheme specified by law. The law requires various kinds of employers to provide health insurance to employees and dependents. Residents who are not eligible for any of the various employee-based insurance schemes should register for national health insurance at with their local municipality.[1]
Insurance normally covers 70% of medical expenses. The individual is responsible for the remaining 30%.
Medical Expenses Deduction
The Medical Expenses Deduction can be claimed on your tax return if you have incurred significant medical expenses (over ¥100,000 or 5% of income for people have less than ¥2M taxable income).
High Medical Expense System
There is a system for capping the maximum amount payable for high-expense medical treatment called the 高額療養費制度 (Kougaku Iryouhi Seido), see the information from the Ministry of Health, Labour, and Welfare (Japanese) and the Japan Health Insurance Association (Japanese).
Post Employment - Optional Continuation
Upon leaving an employer, it may be financially advantageous to chose Optional Continuation, 任意継続(Nini Keizoku) which refers to voluntarily continuing under the Social Insurance, 社会保険(Shakai Hoken) scheme you had with your employer. An alternative option is to move under the National Insurance Scheme 国民健康保険 (Kokumin Kenkou Hoken). It may also be possible for you to become a dependent of another member of your household.
As an employee, your employer covers half of the insurance premium, but as an optional member, you must pay the full amount. This means that premiums can double. However, by law[2] the income band for determining optional contribution premiums is capped to the average income of all members covered by the policy. For Kyokai Kenpo in 2025, this is ¥320,000/month[3], other insurers will differ depending on the average income of its members. If this is less that your monthly salary, or you have dependents that would increase your Kokumin Kenkou Hoken premiums, it's likely advantageous to optionally continue at least initially. As Kokumin Kenkou Hoken is calculated based on previous calendar year's declared income, that may become the lower cost option after some time has lapsed, and potentially within the two year limit of Optional Continuation. Optional Continuation could also be a consideration if you are expecting an increase in income after leaving the job, as premiums are based on final salary, not declared income.
A simple calculator for Optional Continuation premiums. https://taisyoku-shitara.com/keisan/ninikeizoku.html
A more complex calculator providing a comparison of Optional Continuation and National Health Insurance Premiums. It also allows you to specify details of any dependents. https://taisyoku-shitara.com/kenko-006.html
The method to apply is via your employer within 20 days of leaving their employment. The exact method to apply will vary dependent on which scheme are you currently under.
If you see "全国健康保険協会" printed on your Health Insurance card then application is via the branch that covers where you reside. Although your employer may manage the process for you.
- Kyoukai Kenpo Information on Optional Continuation (Japanese)
- List of Kyoukai Kenpo regional offices (Japanese)
If you work for a large employer in a major industry your card may be issued by a 健康保険組合 and the application process will vary based on that entity and they will guide you.
| Item | National Health Insurance (国民保険） | Voluntary Continuation（任意継続） |
|---|---|---|
| Eligibility | Anyone not covered by other insurance schemes |
|
| Coverage Period | Indefinite, as long as conditions are met | 2 years |
| Termination Conditions | When joining another insurance scheme |
|
| Where to apply | At municipal offices | At the branches of the Health Insurance Association in each prefecture |
| Required Documents | Proof of loss of social insurance eligibility | Application process LINK |
| Premium Calculation | Varies by municipality. Determined by previous year's declared income. |
Varies by prefecture. Determined by final salary, subject to upper limit. |
See also
- Japan Pension Service: Employees' Health Insurance System and Employees' Pension Insurance System
- Overview of Medical Service Regime in Japan (PDF) from the Ministry of Health, Labour, and Welfare.
Footnotes
- ↑ National Health Insurance Act. Article 6 lists all other relevant laws and insurance schemes available depending on employment type.
- ↑ Health Insurance Act, Article 47
- ↑ 令和7年度の任意継続被保険者の標準報酬月額の上限について