Health Insurance in Japan: 5 Mistakes That Cost Foreigners

Every foreign resident must enroll in public health insurance — no exceptions. 5 common mistakes (non-enrollment, employer fraud, Myna card, non-payment, coverage gaps) and how to fix each one.

Bottom line: Every foreign resident in Japan must enroll in public health insurance — there are no exceptions for "healthy people" or "short contracts." Getting it wrong costs you retroactive premiums, 100% medical bills, and starting June 2027, possibly your visa. This guide covers the five most expensive mistakes foreigners make and exactly how to fix each one.

Information current as of March 2026 based on MHLW, National Tax Agency, and Immigration Services Agency sources. As the founder of LO-PAL and a former Medical Coordinator for Foreign Patients at a hospital in Osaka, I spent years watching newly arrived residents discover these rules the hard way — usually in the billing office after an emergency visit. This guide exists so you don't have to.

Japan's two public health insurance systems — 30 seconds

Japan runs two parallel systems. Every resident falls into one:

	Shakai Hoken (社会保険)	National Health Insurance / NHI (国民健康保険)
Who	Employees at qualifying companies	Everyone else: freelancers, part-timers below threshold, students, unemployed
Enrollment	Your employer enrolls you	You enroll yourself at city hall
Premium	~9.9% of salary, split 50/50 with employer (FY2026 Kyokai Kenpo average)	Based on last year's income; max ¥1,100,000/year (FY2026)
Coverage	70% covered (you pay 30%)	70% covered (you pay 30%)
Family	Dependents covered at no extra cost	Each family member adds to the premium

Both systems cover the same treatments at the same 70/30 ratio. The difference is who pays the premium and how it's calculated.

Mistake 1: Not enrolling — and getting hit with retroactive premiums

This is the most common and most expensive mistake. Many foreigners assume health insurance is optional, or that they can "enroll later when they need it." It is not optional. Japanese law requires every resident staying 3 months or more to enroll within 14 days of registering at city hall.

If you skip enrollment and later sign up — or get caught — premiums are charged retroactively to your registration date, up to 2 years back. I've seen people at the hospital hit with ¥300,000+ in back premiums on top of a medical bill they couldn't cover.

What to do if you're not enrolled right now

Go to your city hall (市役所 / 区役所) with your residence card (在留カード)
Ask for the National Health Insurance counter: 「国民健康保険の窓口はどこですか？」(kokumin kenko hoken no madoguchi wa doko desu ka?)
Expect back premiums — but you can request a payment plan (分割払い / bunkatsu barai)
If you believe you should be on Shakai Hoken through your employer, see our guide: How to Make Your Employer Enroll You in Shakai Hoken

Mistake 2: Your employer should enroll you — but hasn't

If you work at a company (法人), your employer is legally required to enroll you in Shakai Hoken from day one — regardless of your nationality, visa type, or contract length, as long as you work roughly 20+ hours per week. Many small companies and dispatch agencies (派遣会社) skip this to save money.

Signs you might not be enrolled:

No insurance card from your employer
No 健康保険 deduction on your pay slip
Employer says "foreigners don't need it" or "you're not eligible yet"

If this sounds familiar, read our step-by-step guide to forcing your employer to enroll you in Shakai Hoken. You can also report the violation anonymously to the Pension Office (年金事務所).

Mistake 3: Ignoring the Myna card transition

Japan abolished paper health insurance cards in December 2024. Existing cards expired on December 1, 2025, but a government grace period lets clinics accept them through July 2026 if they can verify your status online. After that, only Myna Hokensho or Shikaku Kakuninsho will work.

If you haven't set up your My Number Card as a Myna Hokensho (マイナ保険証), you need either:

Option A: Register your My Number Card for health insurance at a convenience store kiosk, city hall, or online via the Myna Portal app
Option B: Use a 資格確認書 (shikaku kakuninsho) — a free certificate issued by your insurer that works as an insurance card alternative

Without either one, clinics cannot verify your insurance. You'll be asked to pay 100% upfront. For the complete step-by-step, see our Myna Hokensho transition guide. If you already have a Shikaku Kakuninsho, see our clinic playbook.

Mistake 4: Not paying premiums — your visa is at risk from 2027

This is the newest and most serious consequence. In January 2026, the Japanese government formally adopted a policy linking health insurance and pension payments to visa screening. Starting June 2027, immigration will check your NHI and National Pension payment records when you apply for a visa renewal or status change.

The numbers are stark: of the roughly 970,000 foreigners enrolled in NHI, only 63% are fully paid up. Pension compliance is even lower at 49.7%.

This doesn't mean one late payment kills your visa — screening considers your payment history, whether you've set up a payment plan, and your overall good faith. But chronic non-payment will be grounds for denial.

For the full breakdown of what's coming, who's affected, and how to get current before the deadline, read our insurance non-payment and visa risk guide.

If you're struggling with premiums, don't just stop paying. Contact LO-PAL — a local helper can go with you to city hall and negotiate a reduction or payment plan in Japanese. Post your question for free.

Mistake 5: Assuming everything is covered

Japanese health insurance is excellent for what it covers — but the gaps surprise people. The 70% coverage applies to "medically necessary treatments" as defined by MHLW. Anything outside that list is 100% your cost.

The biggest surprises:

Category	Covered	NOT covered
Dental	Basic fillings, extractions, metal crowns	Implants, ceramic, whitening, orthodontics
Vision	Eye disease treatment	Glasses, contacts, LASIK
Mental health	Psychiatrist visits, medication	Counseling with psychologists (¥6,000–15,000/session)
Childbirth	C-sections, complications	Normal delivery (¥500,000 lump sum instead)
Preventive care	City-provided routine vaccinations	Flu shots, health checkups (人間ドック)

For the complete list of what's covered and what's not — plus how to manage each gap — see our guide to what health insurance won't cover.

What to do if you quit your job

When you leave an employer, your Shakai Hoken coverage ends on your last day. You must switch to NHI or another option within 14 days. Miss this window and you'll have an uninsured gap — any medical costs during that gap are 100% yours.

Your options:

Switch to NHI at city hall — our NHI city hall checklist has exactly what to bring
Join a family member's insurance if your spouse has Shakai Hoken — see our family insurance guide
Continue Kyokai Kenpo voluntarily for up to 2 years (任意継続) — see our voluntary continuation guide

For a complete overview of all your options, read our guide to insurance after quitting.

How to cut your bills when insurance isn't enough

Even with insurance, a hospital stay or surgery can be expensive. Japan has a powerful but little-known system called 高額療養費制度 (kogaku ryoyohi seido) that caps your monthly out-of-pocket medical expenses based on your income. For most working-age residents, the cap is around ¥80,000–¥90,000 per month — no matter how large the bill.

Note: The government is raising these limits in stages starting from August 2025, with further increases planned from summer 2026. The cap will still protect you from catastrophic bills, but the amounts will be higher for some income brackets.

Read our guide to capping hospital bills to learn how to apply before or after treatment.

Useful Japanese at the counter

English	Japanese	Romaji
Where is the health insurance counter?	国民健康保険の窓口はどこですか？	Kokumin kenkō hoken no madoguchi wa doko desu ka?
I want to enroll in health insurance	健康保険に加入したいです	Kenkō hoken ni kanyū shitai desu
Can I pay in installments?	分割払いはできますか？	Bunkatsu barai wa dekimasu ka?
I don't have my insurance card yet	まだ保険証がありません	Mada hokenshō ga arimasen
I want to apply for premium reduction	保険料の減額を申請したいです	Hokenryō no gengaku o shinsei shitai desu
Please issue a certificate of eligibility	資格確認書を発行してください	Shikaku kakuninsho o hakkō shite kudasai

Need help navigating insurance in Japanese? Post your question on LO-PAL for free — a local Japanese helper can accompany you to city hall, call your insurer, or help you set up a payment plan.