National Health Insurance Japan

Last updated: April 2026 · 14 min read

Quick summary: National Health Insurance (NHI) enrollment is mandatory within 14 days of registering your address in Japan — and it’s one of the better deals you’ll get as a foreign resident. This guide covers exactly how enrollment works, how premiums are actually calculated, what’s covered and what isn’t, and the specific situations that confuse almost everyone in their first year.

Table of Contents

1. What NHI is and who needs it
2. How to enroll: step by step
3. How premiums are actually calculated
4. What’s covered — and what isn’t
5. How to actually use your NHI at a hospital or clinic
6. Situations that confuse most foreigners
7. FAQ

1. What NHI Is and Who Needs It

National Health Insurance (国民健康保険, Kokumin Kenkō Hoken, abbreviated NHI or 国保 kokuho) is Japan’s public health insurance system for residents who aren’t covered by an employer’s health insurance plan. It covers 70% of most medical costs, leaving you to pay the remaining 30% at the point of care.

Who needs to enroll

Enrollment is mandatory if you meet both of these conditions:

• You’re staying in Japan for more than 3 months (this applies to almost everyone on a working holiday, student, engineer, or other mid-to-long-term visa)
• You’re not covered by an employer’s health insurance (社会保険, shakai hoken) — if your employer enrolls you in their company plan, you don’t separately enroll in NHI

In practice: working holiday visa holders, students, freelancers, and anyone without full-time Japanese employment enroll in NHI directly through their city hall. Full-time employees at most Japanese companies are automatically enrolled in their employer’s health insurance (shakai hoken) instead — which works similarly but is administered through your employer rather than the city.

This isn’t optional, and skipping it isn’t a viable strategy — unpaid NHI premiums accumulate as a debt tied to your residency record, and unresolved arrears can complicate visa renewals or status changes later. Enroll properly from the start.

2. How to Enroll: Step by Step

Step 1: Register your address first

NHI enrollment requires a registered address. If you haven’t done this yet, it’s the same city hall visit — see the address registration guide for the full process. Most people enroll in NHI in the same visit as their address registration, which is the efficient approach.

Step 2: Go to the NHI counter at city hall

Look for 国民健康保険 (Kokumin Kenkō Hoken) signage, or ask at the information desk. This is usually a separate counter from address registration, though often in the same general area of the building.

Step 3: Bring your documents

• Your Residence Card (updated with your registered address)
• Your passport
• Your My Number, if you have your notification card already (not required at this stage, but useful if you have it)

Step 4: Complete the application form

Staff will help you fill out the enrollment form. You’ll provide basic details — name, address, visa status, and approximate income (more on how this affects your premium in Section 3). For new arrivals with no prior Japanese income, this part is straightforward — you’ll typically be asked to declare zero or estimated income for the assessment period.

Step 5: Receive your insurance card

Your physical NHI card (保険証, hokenshō) typically arrives by mail within 1–2 weeks. Some municipalities issue it on the spot; most mail it. Until it arrives, keep the receipt or temporary documentation from your city hall visit — some clinics will accept this as proof of pending coverage if you need care before your card arrives.

Coverage start date: Your coverage is backdated to the date you became eligible — generally your address registration date — not the date your physical card arrives. If you need medical care during this gap, keep your receipts; you can apply for reimbursement of the 70% portion once your card arrives.

3. How Premiums Are Actually Calculated

This is the part that confuses almost everyone, because the calculation depends on income — and as a new arrival, your “income” situation is genuinely different from a Japanese resident’s.

The basic formula

NHI premiums are calculated based on your previous year’s income, your municipality, your age, and the number of people in your household enrolled in NHI. The exact formula varies by city — Tokyo’s 23 wards each calculate slightly differently from each other and from other prefectures — but the structure is consistent:

• Income-based portion — calculated as a percentage of your previous year’s taxable income
• Per-capita portion — a flat amount per enrolled household member, regardless of income
• Asset-based portion — some municipalities add a small charge based on property ownership (rarely relevant for new foreign arrivals)

Why your first year is usually very cheap

NHI premiums are based on your previous year’s income in Japan. If you arrived this year and had no Japanese income last year, your income-based portion is calculated as close to zero. You’ll still pay the flat per-capita portion, but the total is typically low — often in the range of ¥15,000–30,000 for the year, depending on your municipality and age.

This changes in your second year. Once you have a full year of Japanese income on record, your premium recalculates based on that — and for someone earning a typical working holiday or entry-level salary, the increase is noticeable. Budget for this; it’s a common surprise for people who assumed their low first-year premium was permanent.

How and when you pay

Premiums are typically billed in installments — commonly 10 payments per year (June through March in most municipalities), though some cities offer different schedules. You’ll receive payment slips by mail that can be paid at convenience stores, bank transfer, or in some cases by direct debit from a Japanese bank account once you have one. Missing payments accumulates as an outstanding balance — don’t let this happen; if you’re struggling to pay, contact your city hall directly, as reduced-payment arrangements exist for genuine financial hardship.

4. What’s Covered — and What Isn’t

What NHI covers (you pay 30%)

• Doctor and clinic visits — GP appointments, specialist consultations
• Hospitalization — standard room rates (private rooms cost extra, see below)
• Surgery and major medical procedures
• Prescription medication (dispensed through pharmacies with a doctor’s prescription)
• Basic dental treatment — fillings, extractions, basic crowns
• Maternity care complications (though normal childbirth itself follows a different, separate subsidy system)
• X-rays, blood tests, and standard diagnostic procedures

What NHI doesn’t cover (you pay 100%)

• Cosmetic dental work, orthodontics, implants
• Vision care — glasses, contacts, routine eye exams in most cases
• Private hospital rooms (the difference between standard and private room cost)
• Elective cosmetic procedures
• Some “advanced medical care” (先進医療) treatments designated outside standard coverage
• Medical evacuation or repatriation
• Annual health checkups (基本健診 is sometimes subsidized separately by your municipality — check locally) and comprehensive screening packages (人間ドック)

The high-cost medical expense system: your safety net

This is worth understanding because it caps how bad a worst-case scenario can get. Japan’s high-cost medical expense system (高額療養費制度, kōgaku ryōyō hi seido) sets a monthly ceiling on your out-of-pocket medical costs, based on your income bracket. For most middle-income earners, this ceiling is roughly ¥80,000–90,000 per month — meaning even a major hospitalization with a large total bill won’t cost you more than this ceiling for medical care covered under NHI, once the system is applied.

You can apply for this in advance (obtaining a certificate from your city hall before treatment, if planned) or claim reimbursement afterward. Either way, this system is one of the genuine strengths of Japan’s healthcare system — it prevents the catastrophic medical bankruptcy scenario that exists in some other countries.

5. How to Actually Use Your NHI at a Hospital or Clinic

1. Bring your insurance card to every appointment — show it at reception before you’re seen. Without it, you’ll be charged the full 100% rate upfront (though you can usually claim back the 70% afterward with proper documentation — better to just bring the card).
2. Pay the 30% co-pay at the counter after your appointment, by cash or card depending on the facility — smaller clinics are more likely to be cash-only.
3. Receive any prescription and take it to a pharmacy (調剤薬局, chōzai yakkyoku) — these are typically separate from the clinic itself, often located nearby. Your 30% co-pay applies to the medication too.
4. Keep your receipts — useful for the high-cost medical expense system, tax purposes, and any supplemental insurance claims.

6. Situations That Confuse Most Foreigners

Switching between NHI and employer insurance

If you find full-time employment after enrolling in NHI independently, your employer will typically enroll you in their company health insurance (shakai hoken) instead. You need to formally cancel your NHI enrollment at city hall when this happens — it doesn’t cancel automatically, and you risk being billed for both simultaneously if you don’t.

Leaving Japan temporarily

Short trips abroad don’t affect your NHI status — you remain enrolled and your premium continues. If you’re leaving Japan for an extended period (planning to be gone for months), notify your city hall; depending on the circumstances, this can affect your registration status and premium obligations.

Pregnancy and childbirth

Normal childbirth itself isn’t covered by NHI in the same way as illness or injury — it’s treated as a different category, with its own lump-sum birth allowance system (出産育児一時金) that covers a substantial portion of standard delivery costs, applied for separately through your city hall or insurer. Pregnancy complications, on the other hand, are covered under standard NHI rules. This is a genuinely confusing area — if you’re planning a family in Japan, it’s worth a dedicated conversation with your city hall well before your due date.

Dependents

If your spouse or children are also resident in Japan without their own employer coverage, they typically need to be enrolled in NHI separately (or added to your household enrollment, depending on the municipality’s system) — NHI doesn’t automatically extend family coverage the way employer shakai hoken does for dependents. Confirm the process for your specific household situation at your city hall.

Tax season and NHI premiums

NHI premiums you’ve paid are deductible on your Japanese income tax return (社会保険料控除). This is easy to miss if you’re filing taxes for the first time. Keep your payment records — the annual statement your city hall sends, or your bank/convenience store payment receipts, document this for tax filing purposes.

7. Frequently Asked Questions

What happens if I don’t enroll in NHI?

Enrollment is legally required if you meet the criteria in Section 1. Practically, you may not be actively chased down immediately — but unpaid NHI obligations are tracked against your residency record, and unresolved issues can surface during visa renewal or status change applications. Beyond the legal obligation, going without any health coverage in a country where you don’t have established savings or income history is a real financial risk if anything happens.

Can I use NHI immediately, or is there a waiting period?

Coverage is backdated to your eligibility date (generally your address registration date), so there’s no formal waiting period once enrolled. The practical gap is the time between arriving in Japan and completing your address registration and NHI enrollment — typically your first 1–2 weeks. See the health insurance guide for how to cover this specific window.

How much will I actually pay per month?

This varies significantly by municipality, age, and income — there’s no single national figure. For a new arrival with no prior Japanese income, expect roughly ¥1,500–3,000/month in your first year in most areas. After your first full year of Japanese income is on record, expect this to increase, potentially to ¥8,000–20,000/month depending on your salary and location. Your city hall can give you a more precise estimate for your specific situation during enrollment.

Does NHI cover treatment I need to get back in my home country?

No — NHI only covers treatment received in Japan. If you need medical treatment in your home country, NHI doesn’t apply, and your home country’s healthcare system or insurance arrangements apply instead.

I’m a freelancer with irregular income. How does NHI handle that?

Your premium is recalculated annually based on your previous year’s declared income from your tax filing — not adjusted in real time as your income fluctuates month to month. This means a strong earning year results in a higher premium the following year, even if your income subsequently drops. Freelancers should factor this lag into their financial planning.

Can I get an English-language NHI card or English support at city hall?

The physical card itself is standard and not customized by language. Larger municipalities with significant foreign populations (several Tokyo wards, major cities) increasingly offer multilingual support staff or pamphlets explaining NHI in English and other languages — worth asking when you enroll. The AMDA International Medical Information Center can also help explain Japan’s health insurance system in English if you need additional clarification.

The Bottom Line

NHI is one of the better deals available to foreign residents in Japan — genuinely comprehensive coverage, a real safety net through the high-cost medical system, and premiums that are manageable for most income levels, especially in your first year. The mandatory enrollment within 14 days isn’t a formality to delay; it’s the foundation of your medical safety net for as long as you’re in Japan.

The areas that catch people out — the premium jump in year two, the dependents process, the childbirth subsidy system, what counts as “covered” versus not — are all manageable once you understand the structure. When in doubt, your city hall’s NHI counter is the authoritative source for your specific situation; the rules and amounts vary by municipality more than most guides acknowledge.

What to Read Next

• My Number Card & resident registration: step by step — Do this first; NHI enrollment depends on it
• Best travel & health insurance for foreigners in Japan — Covering the gap before NHI kicks in, and what NHI doesn’t cover
• Banking and sending money from Japan — Setting up automatic payment for your NHI premiums
• Working holiday Japan: complete guide — The full first-month overview

Last updated: April 2026. NHI premium calculations and coverage rules vary by municipality and are subject to change — always confirm current details with your local city hall or ward office.

Have a question about NHI that isn’t covered here, or a different experience in your municipality? Leave a comment — local variations are common and helpful for other readers.