National Health Insurance
国民健康保険 (Kokumin Kenkō Hoken / Kokuho)
If you are not covered by an employer's social insurance (Shakai Hoken), you must enroll in Kokuho — Japan's national health insurance for self-employed people, part-timers, students, and those between jobs. It covers 70% of most medical costs.
"Kokuho is like a neighbourhood medical pool. Everyone in the pool chips in based on their income. When you get sick, the pool pays 70% of your bill — you only pay 30%."
The 'pool' is your city or ward office. Your premium is income-dependent, meaning higher earners pay more. There's a cap so the premium doesn't grow without limit. When you use it at a clinic, show your insurance card and you pay only your copay — the insurer settles the rest directly with the hospital.
You must enrol in Kokuho if you are a resident of Japan and not covered by:
• Employer's Shakai Hoken (社会保険)
• Being a dependent (fuyō) on someone who has Shakai Hoken
• Specific occupational schemes (seamen's insurance, mutual aid associations)
Enrollment is mandatory. You must register at your city hall within 14 days of any change in coverage. Failing to enrol does not exempt you from premium payments — backdated premiums are billed retroactively up to 2 years.
- Doctor and specialist visits (you pay 30% copay)
- Hospitalisation, surgery, and intensive care
- Prescription medications (approved drugs)
- Emergency room treatment
- Mental health and psychiatry visits
- Basic dental: fillings, extractions, root canals
- Childbirth lump-sum grant (出産育児一時金) — ¥500,000
- Funeral expenses grant (葬祭費) — approx. ¥50,000–70,000
- High-cost medical expenses (高額療養費) — monthly copay is capped
- Physical therapy and rehabilitation (prescribed)
- Acupuncture and moxibustion (with doctor referral)
- Medical check-ups if ordered by doctor
- Blood tests, X-rays, and CT/MRI scans (if medically necessary)
- Cancer treatment and chemotherapy
- Cosmetic and plastic surgery (elective)
- Teeth whitening and cosmetic dentistry
- Laser eye surgery (LASIK) — elective vision correction
- Glasses, contact lenses, and hearing aids (adults — children partially covered)
- Fertility treatment and IVF (unless municipality-subsidised separately)
- Routine vaccinations (flu shot, HPV, etc. — some may be municipally subsidised)
- Health check-ups requested by the patient (not prescribed)
- Overseas medical treatment (except emergencies with pre-authorisation)
- Treatments not approved by Japan's medical standards
- Wigs and prosthetics from non-approved providers
- Hospital amenity fees (private room upgrades, special meals)
- Alternative medicine without doctor referral (non-certified)
- Experimental treatments not on the approved drug/procedure list
- Hair loss treatment (e.g. minoxidil for cosmetic purposes)
If your monthly out-of-pocket medical expenses exceed a set threshold (based on income), Kokuho reimburses everything above the cap. For a standard income earner, the monthly cap is approximately ¥80,100 + 1% of costs over ¥267,000. Even if you have a major surgery costing ¥2M, you pay at most ~¥90k–100k out of pocket.
Upon giving birth, Kokuho pays a ¥500,000 lump sum per baby (2023 increase). This is paid directly to the hospital in most cases, so you often pay little or nothing at discharge for a normal delivery.
Kokuho does not pay sick leave (傷病手当金). That benefit is only available under Shakai Hoken (employee insurance). If you are self-employed and get sick, you have no income replacement from the public insurance system — private income protection insurance is strongly recommended.
Adults aged 3–69 pay 30% of all medical bills. Children under 3 pay 20%. Those aged 70–74 pay 20% (10% for low income). Over 75, you join the "latter-stage elderly insurance" with a 10% copay.
Basic dental care is covered at 70% — meaning you pay 30%:
• Fillings with amalgam or standard resin (front teeth)
• Tooth extractions
• Root canal treatment
• Dentures (standard silver metal type)
• Treatment of gum disease (periodontal)
• Emergency pain treatment
Not covered (you pay 100%):
• White porcelain/ceramic crowns on back teeth (aesthetic upgrade)
• Teeth whitening and bleaching
• Metal-free crowns (unless at the front)
• Dental implants (considered elective)
• Invisible/clear orthodontic aligners
• Standard braces (unless medically certified jaw deformity)
If your household income is below ¥330k (2-person household), you may automatically receive a 70% reduction on the per-capita portion. This happens automatically if you file taxes — make sure you file even if you owe nothing.
If you left a job involuntarily (e.g., company layoff, contract not renewed), you may qualify for a 30% income reduction calculation for up to 2 years of premiums. Apply at your city office within the deadline.
iDeCo contributions are deducted from your income before Kokuho calculations. A ¥240,000/year iDeCo contribution could reduce your Kokuho premium by ¥12,000–24,000/year depending on the income-component rate.
If your annual income is under ¥1.3M and a household member has Shakai Hoken, you may be enrolled as their dependent — paying ¥0 in health insurance premiums.