National Health Insurance (NHI) in Japan: A Detailed Guide for Foreign Residents

Roughly 970,000 foreign residents in Japan are enrolled in National Health Insurance — the municipal-run system that covers everyone not on employer-based insurance. If you're a freelancer, student, part-timer, between jobs, or self-employed, NHI is your system.

It works well once you understand it. But the premium calculation is complex, rates differ by municipality, and failing to file an income declaration — even a zero-income one — can cost you thousands of yen in missed reductions. Starting June 2027, unpaid NHI premiums will be grounds for visa renewal denial.

This guide covers everything NHI enrollees need to know: the enrollment process, how premiums are calculated, reduction programs, benefits, payment methods, and the steps to take before the 2027 deadline.

→ This article is part of the Health Insurance in Japan series. For the full system overview, see ① The Complete Guide.

What NHI Is and Who It's For

National Health Insurance (国民健康保険 / Kokumin Kenko Hoken) is Japan's public health insurance system for residents who aren't covered by an employer's plan. It's run by municipalities — your city, ward, town, or village — and everything from enrollment to premium collection to benefit claims happens at your local government office.

You're on NHI if you're: self-employed or freelance, a part-time worker who doesn't meet Shakai Hoken thresholds, a student on a study visa, unemployed or between jobs, a spouse visa holder not covered as a Shakai Hoken dependent, or retired and not continuing employer insurance.

You're not on NHI if you're: enrolled in Shakai Hoken through your employer, a dependent on someone else's Shakai Hoken, aged 75+ (automatically moved to Late-Stage Elderly Insurance), receiving public assistance (生活保護), exempt under a social security agreement with a Certificate of Coverage, or on a short-stay (tourist) visa.

One structural detail that surprises many foreign residents: NHI operates at the household level. Premiums are billed to the head of household (世帯主), and a single notice covers all NHI members in that household. Even if the head of household is on Shakai Hoken, they're still legally responsible for paying the NHI premiums of household members — a concept called "deemed head of household" (擬制世帯主).

The 14-Day Enrollment Rule

You must enroll in NHI within 14 days of the triggering event — typically the day you register as a resident, the day you lose Shakai Hoken coverage, or the day you move to a new municipality. This deadline is codified in the NHI Act Enforcement Regulations, Articles 2 and 3.

Common triggering events: registering your address after arriving in Japan, losing Shakai Hoken after leaving a job, being removed from a spouse's Shakai Hoken as a dependent, transferring residency from another municipality, or ending public assistance.

What happens if you're late: You can still enroll after 14 days, but two consequences follow. First, premiums are charged retroactively to the date your eligibility began, not the date you finally register. If you wait three months, you'll receive a bill for three months at once. Retroactive billing can go back up to two years. Second, any medical costs incurred before enrollment are 100% out of pocket. While some municipalities allow post-enrollment reimbursement claims (療養費), this is not guaranteed and the process is cumbersome. As a rule, assume that medical expenses during the gap won't be covered.

Documents You'll Need

Head to the National Health Insurance counter at your municipal office — usually on the ground floor, often in the same area as resident registration.

New arrival in Japan: Residence Card (在留カード), passport, My Number Card or My Number notification letter. Designated Activities visa holders should also bring the Designation Sheet (指定書) from their passport.

Switching from Shakai Hoken after leaving a job: All of the above, plus the Certificate of Loss of Social Insurance Eligibility (社会保険資格喪失証明書) issued by your former employer. This document is essential — without it, the municipal office cannot process your enrollment. Request it before your last day. If your employer won't issue it, you can request a Confirmation of Enrollment/Withdrawal (健康保険・厚生年金保険資格取得確認通知書) from the Japan Pension Service office.

Transferring from another municipality: Certificate of Moving Out (転出証明書) from your previous municipality, Residence Card, My Number Card. Your NHI withdrawal at the old municipality is processed automatically with your move-out notification, but you must re-enroll at the new location.

Filing through a representative: A letter of delegation (委任状, downloadable from most municipal websites), the representative's ID, and a copy of the enrollee's Residence Card.

If you need medical care before your insurance card or eligibility confirmation arrives, ask the counter staff about issuing a temporary Certificate of Eligibility (資格証明書). Some municipalities provide this on the spot.

Which Visa Types Qualify

The July 2012 amendment to the Basic Resident Registration Act extended resident registration to all foreign nationals with stays of three months or more, bringing them into NHI eligibility simultaneously. Before 2012, the threshold was one year.

Eligible visa types (when not covered by Shakai Hoken): Student, Dependent, Spouse or Child of Japanese National, Permanent Resident, Spouse or Child of Permanent Resident, Long-Term Resident, Designated Activities (including Working Holiday), Technical Intern Training, Specified Skilled Worker, Engineer/Specialist in Humanities/International Services, Business Manager, Professor, Artist, Religious Activities, Journalist, Highly Skilled Professional — all with residence periods of three months or more.

Special cases — under three months but still eligible: If your visa period is under three months but you can demonstrate an expected stay exceeding three months through documentation such as an employment contract, university enrollment letter, or similar evidence, you may still qualify. This applies to certain Entertainer, Technical Intern Training, Dependent, Official, and Designated Activities visas.

Not eligible for NHI: Short-stay (tourist/business) visa holders at 15, 30, or 90 days. Designated Activities sub-categories for medical stay, caregiving for medical stay patients, and sightseeing/recreation (age 18+). Diplomatic visa holders.

How Premiums Are Calculated: Three Components, Three Categories

NHI premiums depend on three factors: where you live, how much you earned last year, and how many people in your household are enrolled. There is no national rate — each municipality sets its own, which means the same income can produce annual premiums that differ by tens of thousands of yen depending on whether you live in central Tokyo or a regional city.

The Three Premium Categories

Your total premium is the sum of three separate calculations:

Medical portion (医療分): Funds the healthcare costs of NHI enrollees. Applies to all members. The 2025 annual cap is ¥690,000.

Late-stage elderly support portion (後期高齢者支援分): Funds the healthcare system for residents 75+. Applies to all members. Cap: ¥240,000.

Long-term care portion (介護分): Funds the long-term care insurance system. Applies only to members aged 40–64. Cap: ¥170,000.

The combined annual premium cap is ¥1,060,000 for FY2025.

The Building Blocks: Income-Based, Per-Capita, and Per-Household

Each of the three categories above is calculated using some combination of these components:

Income-based levy (所得割): Calculated as (Previous year's total income − ¥430,000 basic deduction) × the municipality's income rate. If you had no income in Japan the previous year, this is zero. Typical medical-portion rates range from 6% to 9% depending on the municipality.

Per-capita levy (均等割): A flat amount per NHI enrollee in the household, regardless of income. Typically ¥20,000 to ¥50,000 per person per year for the medical portion alone.

Per-household levy (平等割): A flat amount per household. Some municipalities — notably Tokyo's 23 special wards — don't use this component at all.

Asset-based levy (資産割): Based on fixed property tax. Most municipalities have eliminated this; the dominant calculation methods are now the 2-component system (income + per-capita) or 3-component system (income + per-capita + per-household).

Worked Example: Shinjuku, Tokyo (FY2025 Reference)

Shinjuku uses the 2-component system (income-based + per-capita). For a single person under 40:

Annual income ¥3 million (employment income → ¥2.02M taxable): Medical income levy = (¥2,020,000 − ¥430,000) × 7.58% ≈ ¥120,522 Medical per-capita levy = ¥42,100 Elderly support income levy = (¥2,020,000 − ¥430,000) × 2.39% ≈ ¥38,001 Elderly support per-capita levy = ¥14,200 Total: approximately ¥214,823/year (about ¥17,900/month)

Annual income ¥5 million (employment income → ¥3.56M taxable): Approximately ¥400,000/year (about ¥33,000/month) using the same formula.

First year in Japan, zero income: All income-based levies = ¥0. Per-capita levies only (medical + elderly support) ≈ ¥56,300. With the 70% reduction applied: approximately ¥16,890/year.

These are estimates. Most municipalities provide online premium simulators on their websites — search for your city name plus 国民健康保険料シミュレーション.

Premium Reductions: Up to 70% Off

NHI has two reduction mechanisms: automatic statutory reductions (法定軽減) based on household income, and application-based exemptions (申請減免) for individual hardship.

Statutory Reductions (Automatic)

If the combined previous-year income of the household head and all NHI members falls below certain thresholds, the per-capita and per-household levies are automatically reduced. No application is needed — but income must be declared for the reduction to apply.

70% reduction: Household total income ≤ ¥430,000 + ¥100,000 × (number of earners − 1) 50% reduction: ≤ ¥430,000 + ¥305,000 × number of enrollees + ¥100,000 × (number of earners − 1) 20% reduction: ≤ ¥430,000 + ¥560,000 × number of enrollees + ¥100,000 × (number of earners − 1)

For a single person with zero previous-year income, total household income is well below ¥430,000, triggering the 70% reduction. If your municipality's per-capita levies total ¥56,300, the 70% reduction brings it down to ¥16,890.

Since April 2022, all preschool children (under 6) receive a 50% reduction on per-capita levies regardless of household income. For households already qualifying for statutory reductions, the child discount applies on top of the reduced amount.

Application-Based Reductions

These require visiting your municipal office and filing a request:

Involuntary job loss (会社都合の退職): If you were laid off or your contract was terminated, your previous salary income is reduced by 70% for premium calculation purposes, from the day after separation through the end of the following fiscal year. You'll need your Employment Insurance separation reason code.

Disaster or fire damage: Submit a disaster certificate (罹災証明書).

Significant income decline: If your current income has dropped substantially from the previous year (criteria vary by municipality).

Financial hardship: For situations approaching public assistance eligibility.

Student-specific programs: Some municipalities offer targeted reduction programs for study-visa holders. Check with your local office.

Why Filing an Income Declaration Matters — Even at Zero Income

This is the single most important administrative step that foreign NHI enrollees overlook.

If you're a company employee, your income information is shared with the municipality through year-end tax adjustments. But if you're freelance, self-employed, a student, or newly arrived with no prior Japanese income, the municipality has no income data for you unless you file.

What happens without an income declaration:

Your premiums may be set higher than necessary. Some municipalities calculate premiums using assumed figures for undeclared income, or simply cannot apply the income-based component correctly.

Statutory reductions won't apply. The 70%, 50%, and 20% automatic reductions require confirmed income data. Without a declaration, the system cannot verify that you qualify — so you pay the full per-capita levy amount even if your income is zero.

Your High-Cost Medical Expense Benefit tier defaults to the highest bracket. If you ever need significant medical care, the monthly cap on out-of-pocket costs could be ¥252,600+ instead of ¥35,400.

The fix: Visit the tax counter at your municipal office (separate from the NHI counter but usually in the same building) and file a Resident Tax Declaration (住民税の申告). For a zero-income declaration, you simply confirm that you had no income in the previous calendar year. It takes about 15 minutes and can save you hundreds of thousands of yen over time.

What NHI Covers — And What It Doesn't

As an NHI member, you receive the same core medical coverage as Shakai Hoken enrollees. The copay structure and covered services are identical across both systems.

NHI benefits include:

Standard medical care at 30% copay (20% for children under 6, 20–30% for ages 70+): consultations, diagnostic tests, imaging (MRI, CT), surgery, hospitalization, prescription drugs from the NHI formulary (~16,000+ listed medications), mental health treatment, basic dental care, rehabilitation, and home nursing care.

High-Cost Medical Expense Benefit (高額療養費): Monthly out-of-pocket caps based on income tier. Detailed in ⑦ Costs article.

Lump-Sum Birth Allowance (出産育児一時金): ¥500,000 per child (since April 2023; ¥488,000 at non-participating facilities or births before 22 weeks). The Direct Payment System (直接支払制度) lets the hospital receive this directly, so you only pay the difference at checkout.

Funeral Expense Grant (葬祭費): ¥50,000–¥70,000 paid to the person who arranged the funeral of a deceased NHI member. Amount varies by municipality.

Medical Expense Reimbursement (療養費): If you had to pay full price due to not having your insurance card, or if you received treatment overseas, you can apply for 70% reimbursement after the fact. Overseas claims require an itemized medical statement and receipt translated into Japanese.

What NHI doesn't provide — and Shakai Hoken does:

No Injury & Sickness Allowance (傷病手当金). If illness or injury keeps you off work, NHI provides zero income replacement. Shakai Hoken pays two-thirds of your standard daily wage for up to 18 months.

No Maternity Allowance (出産手当金). NHI members receive the ¥500,000 lump sum but not the income-replacement benefit during maternity leave. Shakai Hoken members get both.

This gap is the most significant practical difference between the two systems for working-age adults, particularly freelancers. If you're self-employed and NHI is your only coverage, consider whether private disability or income-protection insurance makes sense for your situation.

→ Detailed NHI vs Shakai Hoken comparison in ④ Comparison article

How and When to Pay

NHI premiums are calculated on a fiscal year basis (April–March) and typically paid in 10 installments from June through the following March. Your premium notice (保険料納入通知書) arrives by mail in mid-June, addressed to the head of household.

Payment methods:

Direct debit (口座振替) — strongly recommended. Set it up at your municipal office or bank. This is the most reliable way to avoid missed payments, which is particularly important given the 2027 visa enforcement rule.

Payment slips (納付書): Pay at convenience stores, banks, or post offices. Many municipalities now accept smartphone payment apps (PayPay, LINE Pay, etc.).

Pension deduction: For pension recipients aged 65–74, premiums may be automatically deducted from pension payments (特別徴収).

Mid-year enrollment: If you join NHI partway through the fiscal year, premiums are prorated from your enrollment month through March. The notice arrives the month after enrollment, with remaining installments spread across the remaining payment periods.

Mid-year withdrawal: When you switch to Shakai Hoken or leave Japan, premiums are prorated through your last month. Overpaid amounts are refunded — but only if you file a withdrawal notice. If you leave Japan without de-enrolling, premiums continue to accrue.

Switching Between Shakai Hoken and NHI

When you leave a job and lose Shakai Hoken coverage, you have two options: enroll in NHI within 14 days, or continue your former employer's insurance for up to two years through Voluntary Continuation (任意継続).

Voluntary Continuation basics: Premiums are based on your Standard Monthly Remuneration at the time of separation, but you pay the full amount — no employer subsidy. There's a cap (¥300,000 Standard Monthly Remuneration for Kyokai Kenpo), which means high earners may pay less under Voluntary Continuation than NHI. The application deadline is 20 days from the day after separation.

When NHI is likely cheaper: If your previous-year income was low, if you have no dependents, or if you qualify for statutory reductions. When Voluntary Continuation may be cheaper: If your salary was high (above the cap threshold), or if you have family members who would incur additional per-capita NHI premiums.

Compare both options before your last day at work. Your employer's HR department and your municipal NHI counter can both provide estimates.

→ Procedures for leaving Japan and settling NHI in ⑧ Leaving Japan guide

The 2027 Visa Enforcement Rule: What NHI Enrollees Must Do Now

Starting June 2027, the Immigration Services Agency will check NHI premium payment records as part of visa renewal and status change applications. Foreign residents with outstanding premiums will, in principle, be denied.

This primarily affects NHI enrollees because Shakai Hoken premiums are automatically deducted from salary. If you're on NHI, the responsibility to pay — and the consequences of not paying — fall entirely on you.

Your action checklist:

1. Verify your payment status — Visit your municipal NHI counter and confirm whether you have any outstanding premiums.
2. Address any arrears — If you have unpaid premiums, discuss installment payment plans (分割納付). Maintaining an active payment arrangement may prevent a "non-payment" determination during visa screening.
3. File your income declaration — Ensure the municipality has your income data so reductions apply and premiums are correctly calculated.
4. Set up direct debit — Eliminate the risk of future missed payments.
5. Check your move history — If you've changed addresses, verify that NHI enrollment and withdrawal were properly handled at each municipality. Gaps can create arrears you don't know about.

→ Full details on the 2027 rule, who's affected, exceptions, and timeline in ⑥ 2027 Rule Change

Frequently Asked Questions

Q: I just arrived and don't speak Japanese. Can I enroll in English? A: Major cities often have multilingual counters (English, Chinese, Korean, Vietnamese, and others). Many municipalities also publish NHI guidebooks in multiple languages on their websites. If language support isn't available at your office, contact your local International Exchange Association (国際交流協会) — they often provide volunteer interpreter services for government office visits.

Q: I moved but didn't update my resident registration. What happens to my NHI? A: NHI is tied to your registered address. If you move without filing the required move-out and move-in notifications, your NHI remains active at your old municipality. This creates practical problems at medical facilities and, after June 2027, could complicate your visa renewal. Always file your address change within 14 days.

Q: Should I get private insurance on top of NHI? A: NHI covers the vast majority of medical expenses, but it has notable gaps: no income replacement during illness (傷病手当金), no coverage for private room charges (差額ベッド代), and no coverage for the out-of-pocket portion of advanced medical treatments (先進医療). If you're freelance and depend on your ability to work, disability or income-protection insurance deserves consideration.

→ Optimal insurance combinations in ④ NHI vs Shakai Hoken vs Private Insurance

Q: If I leave Japan, do I get a refund on premiums I've already paid? A: Premiums are prorated through your last month of coverage. Any overpayment is refunded, but you must file a withdrawal notice (脱退届) at your municipal office before departure, including a designated refund account. Without the withdrawal notice, premiums continue to accrue.

→ Complete departure procedures in ⑧ Leaving Japan guide

Navigate the Full Series

This article is for general informational purposes and does not constitute legal or tax advice. Premium amounts vary by municipality. Consult your local government office for calculations specific to your situation.

Content is current as of February 2026.

NHI premiums, reductions, and the enrollment process can vary wildly depending on where you live in Japan. What's your experience been like? Did you find the process straightforward, or did you run into unexpected hurdles? Share your story — it might help someone else navigating the same system.