You have just moved to Japan. At city hall, the clerk hands you a form and says 「国民健康保険（こくみんけんこうほけん）に加入してください」. A week later, a coworker tells you not to worry because 「社会保険（しゃかいほけん）に入るから健康保険（けんこうほけん）は大丈夫」. Your pension slip shows 国民年金（こくみんねんきん）. And your new payslip lists 厚生年金（こうせいねんきん）as a deduction.
Four names. All involving either health insurance or pension. All sounding slightly different. And — for many foreign residents — all arriving at the same time with official paperwork attached.
This guide untangles all four terms, explains who pays into each one and why, and helps you understand the key vocabulary you will encounter at city hall, at your company’s HR department, at the pension office, and on official forms. You do not need to be an expert in Japanese tax law. You need to know the right word for your situation — and this article gives you exactly that.
| Term | Reading | Type | Who it covers |
|---|---|---|---|
| 国民健康保険 | こくみんけんこうほけん | Health insurance | Self-employed, students, unemployed, part-time workers without employer coverage |
| 健康保険 | けんこうほけん | Health insurance | Full-time employees and qualifying part-time workers, through their employer |
| 国民年金 | こくみんねんきん | Pension (basic) | All residents aged 20–59, regardless of employment status |
| 厚生年金 | こうせいねんきん | Pension (employee) | Company employees and civil servants, added on top of 国民年金 |
What Does 国民健康保険 Mean?
Municipality-based health insurance
国民健康保険（こくみんけんこうほけん）— often shortened to 国保（こくほ）— is Japan’s municipality-based health insurance program. The word breaks down as: 国民（こくみん）= nation’s people, 健康（けんこう）= health, 保険（ほけん）= insurance. Together: “the people’s health insurance,” meaning health insurance for everyone who is not covered by an employer’s plan.
市区町村が運営（Administration by local governments）
Unlike employee health insurance, which is managed by companies or national associations, 国民健康保険 is administered by your local city, ward, town, or village government — called 市区町村（しくちょうそん）in Japanese. This means you enroll at your local 市役所（しやくしょ）or 区役所（くやくしょ）— city hall or ward office — not at a company.
加入対象者（Who must join）
You are required to join 国民健康保険 if you are a resident of Japan and NOT covered by an employer’s health insurance. This includes:
- Freelancers and self-employed people（フリーランス・自営業者）
- Unemployed people（無職の人）
- Students not covered by a school plan（一般の学生）
- Part-time workers whose employer does not provide social insurance
- People who have recently quit a company and not yet joined a new one
Key sentence: 会社を辞めたので、国民健康保険に入りました。
(Kaisha wo yameta no de, kokumin kenkouho ken ni hairimashita.)
I quit my company, so I enrolled in national health insurance.
保険料の計算（How premiums are calculated）
Premiums for 国民健康保険 are calculated based on your previous year’s income（前年度所得：ぜんねんどしょとく）and the number of people in your household. Because each municipality sets its own rates, the exact amount varies depending on where you live. For new arrivals with no Japanese income history, premiums are often calculated at a minimum rate — but you should confirm this at your local city hall.
保険証（National health insurance card）
Once enrolled, you receive a 国民健康保険証（こくみんけんこうほけんしょう）— your health insurance card. This card lets you receive medical treatment at Japanese hospitals and clinics at a reduced cost, typically paying only 30% of the total fee (with the insurance covering the remaining 70%). Always carry your 保険証（ほけんしょう）— the shortened term — when visiting a doctor.
外国人・留学生の加入（Foreign residents and students）
Foreign residents with a visa of three months or longer are generally required to join 国民健康保険. This includes students on student visas（留学ビザ）, people on working holiday visas, and long-term residents without employer coverage. You must enroll within 14 days of registering your address（住民登録：じゅうみんとうろく）at city hall.
Important note: Some international students receive a partial exemption on premiums. Ask at city hall about 保険料の減額（ほけんりょうのげんがく）— premium reduction — if you have little or no income.
YukaSo if I come to Japan as a student and I am not working for a company, I join 国民健康保険 through my city hall?
ReiThat is exactly right. As a student visa holder without employer coverage, 国民健康保険 is your plan. You register at the ward or city office near where you live — not at your school and not at any company.
What Does 健康保険 Mean?
会社員の健康保険（Employee health insurance）
健康保険（けんこうほけん）— literally “health insurance” — is the employer-based health insurance system in Japan. It covers full-time employees and qualifying part-time workers. Premiums are shared between the employee and the employer, typically on a 50/50 basis. Unlike 国民健康保険, your enrollment is handled automatically by your company when you start work — you do not need to go to city hall.
健康保険 is part of what is called 社会保険（しゃかいほけん）in the employment context — a set of benefits your company enrolls you in when you become a regular employee or a qualifying part-time worker. More on 社会保険 below.
協会けんぽ（Japan Health Insurance Association）
Most employees at small and mid-sized companies are covered by 協会けんぽ（きょうかいけんぽ）— the Japan Health Insurance Association（全国健康保険協会：ぜんこくけんこうほけんきょうかい）. This is the national association that manages 健康保険 for companies that do not have their own plan. If you work for a medium-sized company and you hear 「健康保険証が届きます」 after joining, it is likely a 協会けんぽ card.
健康保険組合（Company union health plan）
Larger corporations often have their own 健康保険組合（けんこうほけんくみあい）— a company-specific health insurance union. Benefits, premium rates, and additional perks (like gym discounts or extra checkups) can vary by company. If you work for a large firm and see a 健康保険組合証 rather than a 協会けんぽ card, this is why.
扶養に入る（Adding dependents to your plan）
One major advantage of 健康保険 over 国民健康保険 is the 扶養（ふよう）system — dependent coverage. If you are enrolled in 健康保険 through your employer, you can add qualifying family members (a spouse, children, parents) as 扶養家族（ふようかぞく）to your plan at no extra premium cost. Those family members receive their own 健康保険証 and are covered for medical visits.
Key condition: A dependent’s annual income（年収：ねんしゅう）must generally be below 1,300,000 yen (130万円) per year to qualify. This threshold is commonly called 「130万円の壁（ひゃくさんじゅうまんえんのかべ）」— the 1.3 million yen wall — a term learners often encounter when reading about part-time work rules.
Example sentences:
- 妻を健康保険の扶養に入れました。
(Tsuma wo kenkouho ken no fuyou ni iremashita.)
I added my wife as a dependent on my health insurance. - 扶養から外れると、国民健康保険に加入する必要があります。
(Fuyou kara hazureru to, kokumin kenkouho ken ni kanyuu suru hitsuyou ga arimasu.)
If you are removed from dependent status, you need to join national health insurance.
Common workplace examples
Here is the vocabulary you will encounter on payslips（給与明細：きゅうよめいさい）and HR documents:
| Japanese | Reading | Meaning |
|---|---|---|
| 資格取得日 | しかくしゅとくび | The date your insurance enrollment begins |
| 資格喪失日 | しかくそうしつび | The date your insurance enrollment ends (e.g., when you quit) |
| 被保険者 | ひほけんしゃ | The insured person (you, the employee) |
| 被扶養者 | ひふようしゃ | A dependent covered under your insurance |
| 健康保険証 | けんこうほけんしょう | Your health insurance card |
What Does 国民年金 Mean?
国民年金 as the basic national pension
国民年金（こくみんねんきん）is Japan’s basic national pension system — the foundation that all residents must pay into. 年金（ねんきん）means “pension” (literally “annual money”). 国民（こくみん）means “the nation’s people.” Together: the pension system for everyone.
If you live and work in Japan for any meaningful period of time, you will encounter 国民年金. The key thing to understand is that it is universal: whether you are a company employee, a student, a freelancer, or a foreign resident, you are expected to pay into this system from age 20 to 59.
20歳以上60歳未満（Age requirement: 20 to 59）
Enrollment in 国民年金 is mandatory for all residents of Japan between the ages of 20 and 59 （20歳以上60歳未満：にじっさいいじょうろくじっさいみまん）. The monthly premium（保険料：ほけんりょう）is a flat amount set by the government each year — around 17,000 yen per month in recent years. This flat rate is the same regardless of income, which is different from employee-based systems where premiums are proportional to salary.
学生納付特例（Student payment deferral）
If you are a student with low income, you can apply for the 学生納付特例制度（がくせいのうふとくれいせいど）— student payment deferral system. This allows you to postpone paying your 国民年金 premiums while you are in school. The premiums are not waived — they can be paid retroactively（追納：ついのう）within 10 years — but this prevents unpaid amounts from piling up during your student years.
免除・猶予（Exemption and deferral）
For people with low income who are not students, there are 保険料免除（ほけんりょうめんじょ）— premium exemption — and 保険料猶予（ほけんりょうゆうよ）— premium deferral — programs. Full or partial exemptions are granted based on household income. Even while exempt, some pension benefit credit still accumulates, which is an important protection for lower-income residents.
基礎年金番号（Basic pension number）
Every person enrolled in Japan’s pension system is assigned a 基礎年金番号（きそねんきんばんごう）— basic pension number. This is a unique 10-digit identifier used across all pension-related paperwork and records. When you start a new job, your company will ask for this number. You receive it on a blue card called 年金手帳（ねんきんてちょう）— pension passbook — though newer enrollees after 2022 receive only a notification letter instead of a physical booklet.
Foreign resident examples
Foreign residents staying in Japan for more than three months are required to enroll in 国民年金. Many foreign residents do not realize this applies to them — but it does, and city hall will typically register you when you complete your address registration（住民登録）.
One term that is especially relevant for foreign residents leaving Japan is 脱退一時金（だったいいちじきん）— lump-sum withdrawal payment. If you were enrolled in 国民年金 (or 厚生年金) as a foreigner, paid into the system, and then permanently leave Japan, you may be eligible to claim a one-time refund of some of the premiums you paid. This must be claimed within 2 years of leaving Japan and renouncing your Japanese address registration.
Example: 日本を離れる前に、脱退一時金の申請を忘れずにしてください。
(Nihon wo hanareru mae ni, dattai ichijikin no shinsei wo wasurezuni shite kudasai.)
Before leaving Japan, do not forget to apply for the lump-sum withdrawal payment.
What Does 厚生年金 Mean?
厚生年金 as the employee pension
厚生年金（こうせいねんきん）is the employee pension insurance system. The word 厚生（こうせい）comes from 厚生省（こうせいしょう）— the former Ministry of Health and Welfare — and carries the meaning of promoting public welfare. 厚生年金 is not a replacement for 国民年金 — it is an additional pension layer that company employees pay into on top of 国民年金.
会社員・公務員（Employees and civil servants）
厚生年金 covers full-time employees（会社員：かいしゃいん）and civil servants（公務員：こうむいん）. Qualifying part-time workers at larger companies are also now included under updated rules. If you work full-time for a company in Japan, you are enrolled in 厚生年金 automatically — there is no separate application.
給与から天引き（Deducted directly from your salary）
厚生年金 premiums are automatically deducted from your monthly salary（給与天引き：きゅうよてんびき）. You will see this line item on your payslip（給与明細：きゅうよめいさい）every month. The premium rate is approximately 18.3% of your standard monthly salary（標準報酬月額：ひょうじゅんほうしゅうげつがく）, and that amount is split equally between you and your employer.
会社と本人で負担（Shared cost between employer and employee）
One of the biggest advantages of 厚生年金 over paying 国民年金 directly is that your employer pays half the premium. If your 厚生年金 contribution is 30,000 yen per month, the company also pays 30,000 yen on your behalf — meaning your effective pension contribution to the system is 60,000 yen per month, with you only paying half of that out-of-pocket.
国民年金への上乗せ（Added on top of 国民年金）
When you pay into 厚生年金 as an employee, you are also simultaneously paying into 国民年金. The 厚生年金 contribution includes your 国民年金 portion — you do not pay both separately. This is why company employees who pay 厚生年金 do not need to pay 国民年金 directly.
The two-layer structure is often described in Japanese as 「1階部分と2階部分（いっかいぶぶんとにかいぶぶん）」— the first floor and second floor of the pension system. 国民年金 is the 1st floor (the foundation everyone shares); 厚生年金 is the 2nd floor (the extra layer for employees).
Common example sentences
- 毎月の給与から厚生年金保険料が天引きされます。
(Maitsuki no kyuuyou kara kousei nenkin houkencryou ga tenbiki saremasu.)
Employees’ pension insurance premiums are deducted from the monthly salary each month. - 会社員は国民年金と厚生年金の両方に加入しています。
(Kaishain wa kokumin nenkin to kousei nenkin no ryouhou ni kanyuu shite imasu.)
Company employees are enrolled in both the national pension and the employee pension. - 厚生年金の保険料は会社と折半します。
(Kousei nenkin no houkencryou wa kaisha to sesshu shimasu.)
The employee pension premium is split equally between the company and the employee.
YukaWait, so if I am a company employee paying 厚生年金, I am also covered for 国民年金 at the same time? I do not pay both separately?
ReiCorrect. When you pay 厚生年金, your 国民年金 is already included inside it. You are building up both pension layers at once through a single payroll deduction. That is one of the real financial advantages of being a company employee in Japan.
国民健康保険 vs 健康保険
Municipality-based vs employer-based
The core distinction is simple: 国民健康保険 is managed by your local government; 健康保険 is managed through your employer. Both provide the same basic coverage rate — you typically pay 30% of medical costs — but the premium calculation, the card you carry, and the rules for dependents are quite different.
| 国民健康保険 | 健康保険 | |
|---|---|---|
| Who runs it | Your city / ward / town office | Your employer (via 協会けんぽ or 組合) |
| Who it covers | Self-employed, unemployed, students, short-stay workers | Full-time employees and qualifying part-timers |
| Premium basis | Based on previous year’s income + household size | Based on monthly salary, shared with employer |
| Dependent coverage | Each family member must enroll and pay separately | Dependents can be added for free（扶養） |
| Where to enroll | City hall / ward office | Company HR handles enrollment |
| Card name | 国民健康保険証 | 健康保険証 |
会社員になる場合（When you become a company employee）
When you start a full-time job at a company that provides social insurance, you will be enrolled in 健康保険 by your employer. If you were previously on 国民健康保険, you must notify your city hall to cancel（脱退：だったい）your 国民健康保険 enrollment. This is called 資格喪失（しかくそうしつ）— loss of eligibility — and you typically have 14 days to report it.
退職した場合（When you leave a company）
When you quit a company, your 健康保険 coverage ends on the day your employment ends（資格喪失日）. From the next day, you have no health insurance until you take one of three actions:
- Join 国民健康保険 at your city hall within 14 days
- Continue your previous 健康保険 through a system called 任意継続（にんいけいぞく）— voluntary continuation — for up to two years (you pay the full premium, including the employer’s share)
- Become a dependent（扶養） on a family member’s 健康保険
Important: Do not wait. Going uninsured even for a few days can mean paying the full cost of any medical treatment you receive during that period.
扶養に入る場合（Joining a family member’s plan as a dependent）
If your spouse or parent is enrolled in 健康保険 and you meet the income threshold (below 1.3 million yen per year), you can join their plan as a 扶養家族（ふようかぞく）for free. This is popular among non-working spouses and part-time workers who stay below the income limit. Your enrollment is handled through your family member’s company HR — not at city hall.
保険証の違い（Differences in the insurance card）
Both cards look similar and are accepted at virtually all hospitals and clinics in Japan. The key difference is what is printed on them: 国民健康保険証 will show the name of your city or ward; 健康保険証 will show your company’s plan name (e.g., 全国健康保険協会 or your company’s 組合 name). The card you carry tells medical staff which system you are enrolled in.
Common mistakes
Mistake 1: Not canceling 国民健康保険 when joining a company. If you forget to report 資格喪失 at city hall, you may receive bills for both plans at the same time.
Mistake 2: Assuming 健康保険 automatically includes your family. Dependents must be formally added via your company HR — they do not join automatically just because you are enrolled.
Mistake 3: Thinking national health insurance and social insurance are the same thing. 国民健康保険 is one specific program; 社会保険（しゃかいほけん）usually refers to the combination of 健康保険 + 厚生年金 in an employment context, which is a different system entirely.
国民年金 vs 厚生年金
Basic pension vs employee pension
国民年金 is the foundation that everyone pays into. 厚生年金 is an additional layer that only company employees and civil servants pay into, built on top of 国民年金. When you retire and draw your pension, your total monthly benefit comes from both layers if you were an employee — which is why company employees generally receive higher pension payments than people who only paid into 国民年金.
1階部分と2階部分（The two-floor pension structure）
The Japanese pension system is often visualized as a building with two floors:
| Layer | Pension | Who pays | Benefit at retirement |
|---|---|---|---|
| 1階部分（basic floor） | 国民年金 | All residents aged 20–59 | Basic old-age pension（老齢基礎年金：ろうれいきそねんきん） |
| 2階部分（upper floor） | 厚生年金 | Company employees and civil servants | Employee old-age pension（老齢厚生年金：ろうれいこうせいねんきん）added on top |
会社員の場合（If you are a company employee）
As a company employee, you pay 厚生年金 through payroll deduction. This payment includes your 国民年金 contribution — you never pay 国民年金 separately. When you retire after a sufficient contribution period, you receive both 老齢基礎年金 (the basic portion from 国民年金) and 老齢厚生年金 (the additional portion from 厚生年金).
フリーランスの場合（If you are self-employed or freelance）
If you are a freelancer or self-employed person, you pay 国民年金 directly at a flat monthly rate — there is no 厚生年金 for you unless you voluntarily join a separate iDeCo（個人型確定拠出年金：こじんがたかくていきょしゅつねんきん）plan. This means your retirement benefit will generally be lower than a company employee’s, which is why many freelancers in Japan supplement their pension savings through other means.
保険料の払い方（How premiums are paid）
| 国民年金 | 厚生年金 | |
|---|---|---|
| Payment method | Paid directly by the individual（納付書・口座振替） | Deducted from monthly salary（給与天引き） |
| Premium rate | Flat amount (approx. 17,000 yen/month in recent years) | Approx. 18.3% of standard monthly salary, split with employer |
| Employer share | None (individual pays 100%) | Employer pays 50% |
| Coverage | 国民年金 only | 国民年金 + 厚生年金 combined |
Common learner mistakes
Mistake 1: Thinking company employees pay 国民年金 separately. They do not — 厚生年金 covers both layers. The confusion arises because 国民年金 sounds universal (and it is), but the payment mechanism differs by employment type.
Mistake 2: Assuming 国民健康保険 covers pension. It does not. 国民健康保険 is health insurance only. Pension (国民年金) is a completely separate system with a separate payment.
Mistake 3: Leaving Japan without claiming 脱退一時金（だったいいちじきん）. Foreign residents who have paid into Japan’s pension system for 6 months or more and permanently leave Japan can apply for this lump-sum refund within 2 years of departure. The application goes to the Japan Pension Service（日本年金機構：にほんねんきんきこう）. Missing this deadline means losing those contributions permanently.
社会保険とは何か — What Is 社会保険?
社会保険 as an umbrella term
社会保険（しゃかいほけん）— social insurance — is an umbrella term that can refer to Japan’s entire system of public insurance programs. In the broadest sense, it includes:
- 健康保険（けんこうほけん）— health insurance
- 厚生年金保険（こうせいねんきんほけん）— employee pension insurance
- 雇用保険（こようほけん）— employment insurance (unemployment benefits)
- 労働者災害補償保険（ろうどうしゃさいがいほしょうほけん）— workers’ accident compensation insurance
- 介護保険（かいごほけん）— nursing care insurance
健康保険 + 厚生年金 = 社会保険 in employment context
In everyday workplace Japanese, however, 社会保険 almost always refers specifically to the combination of 健康保険 and 厚生年金保険 that an employer enrolls you in. When a job listing says 「社会保険完備（しゃかいほけんかんび）」— full social insurance provided — it means the company will enroll you in both 健康保険 and 厚生年金. This is one of the standard markers of a full-time, legitimate employment contract in Japan.
Example: この求人票には「社会保険完備」と書いてあります。
(Kono kyuujinhyou ni wa “shakai hoken kanbi” to kaite arimasu.)
This job posting says “full social insurance provided.”
Missing city hall procedures after leaving a job
One of the most common practical mistakes foreign residents make is not going to city hall promptly after leaving a company. When your 健康保険 ends（資格喪失）, you need to:
- Return your old 健康保険証 to your former employer
- Enroll in 国民健康保険 at your city hall within 14 days, OR
apply for 任意継続（にんいけいぞく）through your former insurer, OR
join a family member’s 健康保険 as a dependent - If you were paying 厚生年金 and will now be self-employed or unemployed, begin paying 国民年金 directly
Skipping step 2 does not make the obligation disappear — it can result in backdated premium bills for the months you were technically uninsured.
Confusing 扶養 and the dependent visa
A note for foreign residents: the word 扶養（ふよう）in the context of health insurance refers to being a financial dependent on someone’s 健康保険 plan. This is separate from the 家族滞在ビザ（かぞくたいざいビザ）— dependent visa — which is an immigration status. You can be on a 家族滞在ビザ and still need your own 国民健康保険 if you do not qualify for 扶養 coverage. Do not assume that having a dependent visa means you are automatically covered under a family member’s 健康保険.
Decision Rule: Which Word Do You Need?
Use these questions to identify the right term for your situation.
Are you talking about MEDICAL / HEALTHCARE insurance?
YES
|
+-- Are you enrolled through a company employer?
| YES --> Use 健康保険（けんこうほけん）
| Examples: 健康保険証, 協会けんぽ, 健康保険組合, 社会保険
|
+-- Are you self-employed, a student, unemployed, or not covered by a company?
YES --> Use 国民健康保険（こくみんけんこうほけん）/ 国保
Examples: 国保に加入する, 市役所で手続き, 国民健康保険証
Are you talking about RETIREMENT PENSION?
YES
|
+-- Are you a company employee or civil servant?
| YES --> Both 国民年金 AND 厚生年金 apply to you.
| You pay 厚生年金 through payroll — 国民年金 is included inside it.
| Examples: 厚生年金保険料, 給与天引き, 老齢厚生年金
|
+-- Are you self-employed, a student, or not employed by a company?
YES --> Use 国民年金（こくみんねんきん）
Examples: 国民年金の保険料, 納付書, 学生納付特例, 脱退一時金
Are you talking about YOUR COMPANY'S BENEFITS PACKAGE?
YES --> Use 社会保険（しゃかいほけん）as the umbrella term
It typically means 健康保険 + 厚生年金 together
Look for: 社会保険完備 on job postings
Are you a FOREIGN RESIDENT leaving Japan permanently?
YES --> Check eligibility for 脱退一時金（だったいいちじきん）
Apply within 2 years to Japan Pension Service（日本年金機構）
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Quick Quiz
Test what you have learned. Choose the correct term from: 国民健康保険, 健康保険, 国民年金, 厚生年金, 社会保険, 脱退一時金. Answers are below.
- You are a freelance graphic designer in Tokyo. You have no employer. Which health insurance plan must you join?
_______ - You just started a full-time job at a Japanese company. Your payslip shows a deduction labeled 「______保険料（ほけんりょう）」— it is your employee pension deduction.
- All Japanese residents aged 20 to 59 are required to be enrolled in ______.
- Your friend works full-time for a company and wants to add their non-working spouse to their health insurance plan for free. This arrangement is called 扶養, and it is possible because the friend is enrolled in ______.
- A job posting says 「______ 完備」. This means the company provides full health insurance and pension coverage as part of employment.
- You are a foreign resident who paid into Japan’s pension system for two years and are now permanently returning to your home country. Within two years of leaving, you may be eligible for a ______.
Answers:
- 国民健康保険（こくみんけんこうほけん）— Freelancers with no employer coverage must enroll through city hall.
- 厚生年金（こうせいねんきん）— The payroll deduction line for employee pension insurance.
- 国民年金（こくみんねんきん）— The universal basic pension. All residents 20–59, regardless of job type, must pay in.
- 健康保険（けんこうほけん）— Only the employer-based plan has free dependent coverage. 国民健康保険 requires separate enrollment for each family member.
- 社会保険（しゃかいほけん）— “社会保険完備” on a job listing means the employer provides 健康保険 + 厚生年金 coverage.
- 脱退一時金（だったいいちじきん）— The lump-sum withdrawal payment for foreign residents who have left Japan permanently. Apply within 2 years through the Japan Pension Service.
Have you encountered 国民健康保険, 健康保険, or 国民年金 on official paperwork during your time in Japan? Which part of the system was most confusing for you? Share your experience in the comments!
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