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.

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 under the Health Association Insurance Scheme

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. The full term for this Optional Continuation is 政府管掌健康険剣の任意継続（協会けんぽ). 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.

By selecting Optional Continuation, contributions will potentially be capped at a monthly Standard Remuneration amount of ¥300,000 per month (based on your income when leaving employment). If this is less that your monthly salary it's likely advantageous to optionally continue at least initially. As the National Insurance Scheme will be 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.

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	Must have been enrolled in social insurance for 2 months or more Apply within 20 days after leaving the job
Coverage Period	Indefinite, as long as conditions are met	2 years
Termination Conditions	When joining another insurance scheme	When 2 years have passed since joining When there has been even a single day of non-payment When getting a job and joining social insurance
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	Varies by prefecture

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.