What Is Japan’s National Health Insurance? A Complete Guide for Foreign Residents

Living in Japan means enjoying amazing food, safe streets, and a world-class transportation system—but sooner or later, you’ll also need to deal with something extremely important: health insurance.
If you’re planning to stay mid- to long-term, you’ll almost certainly come across the term National Health Insurance, often shortened to NHI or Kokumin Kenkō Hoken (国民健康保険).

Let’s walk through it step by step so you can navigate Japan’s healthcare system with confidence.

What Exactly Is the National Health Insurance (NHI)?

National Health Insurance is Japan’s public health insurance program for people who are not covered by Employer Health Insurance (known as “Shakai Hoken”).
It is run by your local city, ward, town, or village office.

The system is designed to make healthcare affordable. Once you join NHI, you usually pay only 30% of medical costs when visiting hospitals, clinics, and specialists. The insurance covers the remaining 70%.

Foreign residents living in Japan for more than 3 months must generally join a public health insurance program—either Employer Health Insurance or NHI.

In other words:
If you live here, you’re expected to join. And yes, foreigners are absolutely eligible.

Who Needs to Join?

You need to enroll in NHI if:

• You live in Japan and have a Residence Card
• Your stay is longer than 3 months
• You are not enrolled in company health insurance

Typical situations include:
• Language school students
• University students
• Freelancers
• Working holiday holders
• Part-time workers
• Unemployed residents
• Self-employed residents

If you join a company full-time and receive Shakai Hoken, you leave NHI automatically.

One important fact:
Health insurance in Japan is not optional.
Even if you try to avoid joining, the city office can charge you retroactively when you eventually register.

Why Foreigners Must Join

Japan uses a universal healthcare system. Every resident—Japanese or foreign—must be insured to guarantee access to affordable healthcare.

This ensures that:
• No one avoids hospitals due to cost
• Medical fees are standardized
• Financial risks from unexpected illness are reduced

And frankly, it protects you.
Japan’s medical bills without insurance can be extremely high.

What Are the Benefits?

Once you are enrolled, you get access to:

1. 70% Cost Coverage

You pay only 30% of most medical costs.
Children often pay 20% or less (depends on the city).

2. Dental Coverage

This surprises many foreigners — Japan’s public insurance covers dental care such as:
• Fillings
• Cleanings
• Cavities
• Root canals
• Simple extractions

Cosmetic work like whitening is not covered.

3. Prescription Medicine

Pharmacies also fall under the 30% out-of-pocket rule.

4. High-Cost Medical Expense Reimbursement

If your medical bill is extremely high, NHI refunds the excess later.
This prevents you from paying huge amounts all at once.

→About the High-Cost Medical Expense System

5. Maternity Benefits

NHI provides financial support for childbirth (around ¥500,000 per birth in many cities).

6. Travel Coverage

If you become sick while traveling inside Japan, your NHI still applies.

Overall, the system is generous and very foreigner-friendly.

How to Join the National Health Insurance

Enrolling is simple. You must register within 14 days of moving into your new city.

Where to enroll

Go to your City Hall (市役所) or Ward Office (区役所).

What to bring

• Residence card
• Passport
• MyNumber (if you have one)
• Certificate of residence (Juminhyo, if required)
• Proof of previous insurance (optional but useful)

What happens during registration

• You fill out a short form
• Staff will calculate your estimated premium
• You receive your NHI insurance card (sometimes mailed later)

And you’re officially covered.

How Much Does National Health Insurance Cost?

This is the question everyone asks.

NHI premiums vary depending on:

1. Your annual income (previous year’s income in Japan)
2. The city you live in
3. Number of people in your household

Because every city has its own calculation method, two people with the same income may pay different amounts depending on their city.

However, most premiums fall between:

Typical Monthly Premium Range

• ¥8,000 – ¥25,000 per month for a single adult
• ¥12,000 – ¥40,000 per month for families

If you just arrived in Japan and had no income the previous year, many cities set your premium to the minimum rate, often around:

→ ¥4,000 – ¥8,000 per month

How Premiums Are Calculated

Although formulas vary, most cities calculate using:

• Income-based amount
• Per-person amount
• Flat household fee
• Medical support fee
• Care insurance fee (age 40–64 only)

This can look complicated, but ultimately it’s based on:

Higher income = higher premiums.
Lower income = cheaper premiums.

Realistic Example Calculations

Below is a simple, easy-to-understand sample.
(Actual numbers vary by city—this is just for explanation.)

Example A: New arrival in Japan (previous year income: ¥0)

Example B: Full-time freelancer earning ¥3,000,000/year

Example C: Married couple, combined income ¥5,000,000

These examples show why income matters a lot.

Reductions and Discounts

Many foreigners don’t know this—but NHI has helpful reductions.

You may receive discounts if:
• You had very low income the previous year
• You just arrived in Japan
• You recently lost your job
• You are a student
• You experienced a disaster or financial hardship

Some reductions are automatic, others must be requested.
Always ask the city office if you are eligible.

What Happens If You Don’t Join?

If you avoid joining even though you should:

• You may be charged back payments for the months you were uninsured
• You may face penalties
• You will be 100% responsible for your medical bills
• You may be refused certain procedures until you enroll

Japan takes health insurance compliance seriously.

Final Thoughts

Japan’s National Health Insurance system may look complicated at first, but it is one of the most reliable and fair healthcare systems in the world.
Whether you’re a student, freelancer, or new resident, joining NHI ensures you receive affordable healthcare, peace of mind, and access to Japan’s high-quality medical services.

If you’re living in Japan long-term—don’t skip it.
You’ll be grateful the moment you need a doctor or dentist.

Thanks for reading!

Reference link: Tokyo Health Insurance Bureau