Japan’s health insurance system is one of the cheapest and most comprehensive in the world for residents — but enrolling correctly as a foreign family takes a few steps. This guide explains the two main systems (employer-based vs National Health Insurance), how dependents work, what kids’ medical subsidies cover, and how monthly premiums are calculated.
Bottom line: every resident must enroll within 14 days of registering an address. Failing to enroll means paying 100% out-of-pocket, which adds up fast.
The two systems
Employer health insurance (Kenkou Hoken / Shakai Hoken)
- For full-time employees of Japanese companies (incl. Japan-incorporated foreign company branches)
- Premium ~5% of salary, split 50/50 with employer
- Spouse and kids enrolled as dependents — no extra premium
- Covers 70% of medical costs (you pay 30%)
- Auto-enrolled by HR on first paycheck
National Health Insurance (Kokumin Kenkou Hoken / NHI)
- For freelancers, students, retirees, anyone not on employer insurance
- Premium based on previous year’s income — first year is fixed-low because no Japan income yet
- Each adult pays separately; kids ride on parent
- Covers 70% of medical costs
- Enroll at ward office within 14 days of address registration
Which one applies to your family
- Spouse visa holder + working spouse: working spouse on employer insurance; spouse + kids as dependents → free
- Spouse visa, both not employed: NHI for both adults; kids on whichever parent’s NHI
- Self-employed/freelance: NHI
- Student visa: NHI mandatory
- Multiple visa types in family: each adult on appropriate type; kids on either parent
Premium math (NHI example)
- Year 1 in Japan (no prior Japan income): ~¥3,000–5,000/month per adult — flat low rate
- Year 2+: calculated from prior year’s tax-declared income, typical family premium ¥20,000–60,000/month for two adults
- Premium is income-tier based, capped per ward
- If income drops, premium adjusts downward at next renewal
- Kids: no extra premium beyond parents
Children’s medical subsidy (Kodomo Iryou-hi Joyo)
- Fukuoka City: kids age 0–12 (some wards extend to 15 or 18) get co-pays subsidized to ¥0–500 per visit
- Apply at ward office after enrolling in NHI/employer insurance
- Receive child medical card (kodomo iryou-sho) by mail in 1–2 weeks
- Show this card alongside insurance card at clinics
- Income-tested in some wards — high earners may pay full 30% co-pay
Enrollment steps for new arrivals
Step 1: Register address
Move into apartment → ward office within 14 days → bring residence card + lease + passport. You’ll get the Juminhyo (resident certificate).
Step 2: Enroll in insurance
- If on employer insurance: HR will arrange; start date = your hire date
- If on NHI: same ward office visit, ask for kokumin kenkou hoken
- Hours: Mon-Fri 8:45–17:15 (closed weekends/holidays)
Step 3: Apply for child medical card
- Same ward office visit; bring kid’s residence card + insurance card
- Wait 1–2 weeks for card by mail
- Until card arrives, save receipts — reimbursable retroactively
Step 4: Set up high-cost medical insurance
- Japanese system has a monthly cap (kougaku ryouyou-hi seido) — typically ¥30,000–80,000/month max out-of-pocket regardless of treatment
- Apply for cap-coverage limit certificate (gendogaku ninteishou) before major procedures
- Otherwise pay then claim refund — slower but works
What’s covered
- Outpatient visits, hospitalization, surgery, prescriptions, imaging — all covered at 70% (or 0–30% for kids with subsidy)
- Dental: covered for cavities, extractions, basic care; cosmetic excluded
- Vision: limited — basic eye exams covered, glasses not
- Mental health: covered for psychiatric care; talk therapy varies
- Maternity: separate one-time grant (¥420,000) for birth; outpatient prenatal care covered
What’s not covered
- Cosmetic surgery, orthodontics (most), elective procedures
- Preventive care like annual physicals (employers usually pay for kenkou shindan separately)
- Voluntary vaccinations (mumps, flu, HPV before recent re-listing, etc — though city subsidies cover some)
- Some imported drugs not on Japan’s approved list
Travel insurance vs Japan insurance
- Japanese insurance covers you only inside Japan
- For travel outside, supplement with travel insurance
- Conversely, foreign travel insurance won’t cover routine care in Japan
- Some employer-based plans extend coverage internationally; check policy
If you leave Japan
- De-register at ward office before leaving (return insurance card)
- NHI premiums prorated to month of departure
- If returning later, re-enroll — premium calculation resets if you’ve been gone 1+ year
Common questions
Can I keep my home country insurance?
You can carry it as supplemental but Japan still requires NHI/employer insurance for residents. Most foreign insurance won’t cover Japan-based care anyway.
What about pre-existing conditions?
Japan’s system has no pre-existing condition exclusions. Day 1 of coverage = full coverage.
Does insurance cover Japanese alternative medicine?
Some kampo (Japanese herbal) prescriptions are covered. Acupuncture covered if doctor-referred. Massage and chiropractic typically not covered.