Shakai Hoken vs Kokumin Hoken: Which Insurance Should You Choose in Japan?

Quick answer (30 seconds): If you're a full-time company employee, you're automatically in shakai hoken (社会保険) — a bundle of employee health insurance plus employees' pension (kosei nenkin), split roughly 50/50 with your employer. If you're self-employed, a freelancer, a student, unemployed, or a part-timer below the enrollment threshold, you pay into kokumin kenko hoken (国民健康保険, "Kokuho") for health coverage and kokumin nenkin (国民年金) for pension separately, entirely out of your own pocket. The single biggest practical difference is dependents: shakai hoken lets you add a spouse or child at no extra premium; Kokuho charges per household member. Shakai hoken also pays sickness and maternity leave allowances that Kokuho generally does not. When you quit a job, you get three choices — keep your old insurance up to two years (nini keizoku), switch to Kokuho, or become a family member's dependent — and picking the wrong one can cost real money.

Disclaimer: General information, not tax, legal, or insurance advice. Premiums, thresholds, and reform dates change; confirm your own numbers with your employer's HR, your city/ward office, or the Japan Pension Service (日本年金機構) before deciding.

Two systems, never both, never neither

Japan has universal health coverage, and everyone legally resident for three months or more must be in exactly one public health system — never both, never neither. Which one depends on how you work, not on nationality:

• Shakai hoken (社会保険) — full-time company employees and qualifying part-timers. Your employer enrolls you automatically.
• Kokumin kenko hoken (国民健康保険, "Kokuho") — the residual category: self-employed, freelancers, students, unemployed, retirees, and part-timers under the shakai hoken thresholds. You enroll yourself at the city/ward office.

New to Japan and not sure which applies yet? Start with our enrollment guide for newcomers. If you already know you're a Kokuho case, our complete Kokuho guide covers enrollment, premiums, and the 2027 visa-payment rule. This article assumes you know roughly which bucket you're in and focuses on the comparison and the decision — especially at a job change, resignation, or move to freelancing.

What's bundled together — and what isn't

The most common confusion: shakai hoken is a package deal, Kokuho is not.

• Shakai hoken bundles employee health insurance (kenko hoken) and employees' pension (kosei nenkin, 厚生年金) into one payroll deduction — see our payslip breakdown for how it appears on your pay stub.
• Kokuho is health insurance only. If you're not on shakai hoken, you must separately enroll in kokumin nenkin (国民年金) — a different system with its own flat-rate premium. "Kokumin hoken" does not cover your pension; two enrollments, two bills, no employer contribution to either.

Side-by-side: shakai hoken vs kokumin hoken

	Shakai hoken (employee)	Kokumin hoken (Kokuho + kokumin nenkin)
Who it's for	Full-time employees; part-timers clearing the hours/size test	Self-employed, freelancers, students, unemployed, part-timers below the threshold
How you join	Employer enrolls you automatically	You enroll yourself at the city/ward office
What's included	Health insurance + pension, one package	Health (Kokuho) and pension (kokumin nenkin) are separate enrollments
Who pays	Split ~50/50 with your employer	You pay the full amount — no employer share
Health premium basis	% of standard monthly remuneration — FY2026 Kyokai Kenpo average 9.90%, split 50/50	Set by your municipality from prior year's income plus per-person/per-household amounts
Pension premium	Kosei nenkin: 18.3%, split 9.15%/9.15%	Kokumin nenkin: flat ¥17,920/month (FY2026), regardless of income
Dependents (fuyou)	Spouse/children under the income line added at no extra premium	No dependent concept — every household member billed individually
Non-working spouse's pension	Can become "Category 3" insured (第3号被保険者) — ¥0 pension premium, still earns credit	Spouse pays the full ¥17,920/month themselves (unless exempted)
Sickness allowance	Yes — ~two-thirds of average daily pay, up to a cumulative 1 year 6 months	Discretionary by municipality; essentially never paid for ordinary illness
Maternity leave allowance	Yes — paid during pre/post-natal leave	No
Childbirth lump-sum	Yes (~¥500,000)	Yes — same benefit, not a differentiator
High-cost medical cap	Applies (see our guide)	Applies equally

The single biggest difference: dependents (fuyou)

If you remember one thing, make it this: Kokuho has no dependent status.

Under shakai hoken, if your spouse or child earns under roughly ¥1.3 million a year (¥1.8 million if 60+ or certain disabilities) and less than half your income, you can register them as your fuyou (被扶養者). They get full coverage, and a dependent spouse can also become a Category 3 insured person (第3号被保険者) — ¥0 pension premium, while still building basic pension credit. One salary, one shakai hoken premium, whole household covered.

Kokuho has no dependent registration. Every household member not covered elsewhere is added to the bill, and the total rises per person. A non-working spouse also owes their own ¥17,920/month kokumin nenkin unless they qualify for a reduction (see our pension exemption guide).

Takeaway: the more dependents you support, the more shakai hoken tends to win, since Kokuho charges per head. A single person with no dependents may find the gap much smaller — sometimes reversed, depending on income and municipality.

⚠️ From April 2026, the dependent income test changes: eligibility will use your labor-contract-based projected income (excluding overtime) rather than actual/forecast earnings, so a temporary overtime spike shouldn't cost you dependent status. Confirm the current rule with the relevant health insurance association before relying on it.

Sickness and maternity allowance: a shakai hoken-only benefit

If illness keeps you off work, shakai hoken pays a sickness allowance (傷病手当金) — roughly two-thirds of your average daily standard remuneration, for up to a cumulative 1 year 6 months. Kokuho does not offer an equivalent as a matter of course: municipalities can create their own ordinance for it, but in practice almost none do.

Same for childbirth: shakai hoken pays a maternity leave allowance (出産手当金) during pre/post-natal leave; Kokuho members do not receive this. Both systems pay the separate one-time childbirth lump-sum (出産育児一時金, ~¥500,000) — don't confuse the two; the lump-sum is not a differentiator, the leave-period income replacement is.

If you're self-employed and this gap worries you, private income-protection insurance is the one place a private product genuinely fills a real hole in Kokuho, rather than duplicating cover you already have.

Freelancers and sole proprietors: automatically Kokuho + kokumin nenkin

Filing a kaigyo todoke (開業届) or otherwise working for yourself doesn't create a separate "freelancer insurance" choice — once you're not an employee, you fall into the residual category: Kokuho for health, kokumin nenkin for pension, both self-enrolled and self-paid, no employer share on either. For registration steps, see our sole proprietor guide.

Two things catch new freelancers off guard:

• Year one is often cheap, year two isn't. Kokuho is based on prior year's income, so a lean first freelance year keeps the bill low — and it jumps once a full year of freelance income is on record.
• There's no employer half. An employee effectively pays half of a ~9.90% health premium and half of the 18.3% pension rate; a freelancer pays the Kokuho equivalent plus the full ¥17,920/month kokumin nenkin alone. Check the pension exemption guide if a lean year makes that flat premium genuinely unaffordable.

Part-time work in 2026: when do you get pulled into shakai hoken?

Whether you personally must join your employer's shakai hoken depends on:

• Weekly scheduled hours — 20 hours or more is the core trigger.
• Employer size — historically only larger employers had to enroll qualifying part-timers; this is being phased down: 36–50 employees from October 2027, 21–35 from October 2029, 11–20 from October 2032.
• Monthly wage — changing October 2026. Part-timers also needed roughly ¥88,000/month or more (the "¥1.06 million wage wall") to be pulled in. From October 2026, this wage test is scheduled for abolition — once your employer clears the size threshold, 20+ hours a week is expected to trigger enrollment regardless of pay.

In plain terms: keeping hours or pay just under the old limits to stay a dependent is getting harder, because the wage lever is disappearing and the size threshold keeps expanding. If you rely on dependent status through a spouse or parent, 20 hours a week is the line to watch — confirm your contracted hours with HR. Moving to your own shakai hoken isn't necessarily bad: you gain sickness/maternity allowance and your own kosei nenkin record, but your paycheck changes.

Quitting your job: your three insurance choices

Related reading: if you're using a taishoku daiko (退職代行, resignation agency) to leave, see our full quitting guide for the resignation process itself; this section covers what happens to your insurance afterward. Your shakai hoken ends on your last day, and you must be covered again within 14 days. You have three options:

Option	How it works	Cost pattern	Best if
1. Voluntary continued insurance (nini keizoku, 任意継続被保険者)	Keep your old health coverage up to 2 years. Apply within 20 days of leaving (needs 2+ months prior coverage).	Former standard monthly remuneration (capped at the FY2026 ceiling of ¥320,000) × your prefecture's rate, but you now pay both shares — roughly double your last paycheck deduction, fixed for up to 2 years (voluntary cancellation allowed anytime)	You have dependents — still covered at no extra premium
2. Switch to Kokuho	Enroll at your city/ward office within 14 days	Based on prior year's income plus per-person/household amounts, set by your municipality	You're single with no dependents, or a real quote is lower
3. Become a family member's dependent	Spouse/parent's shakai hoken adds you as fuyou if your going-forward income is low enough	¥0	A qualifying working spouse/parent is available — nothing beats free

How to decide, in order: First, check whether option 3 applies — free beats everything. If not, get real numbers from HR (nini keizoku premium) and your city/ward office (Kokuho estimate) before the 20-day deadline; don't guess, since the gap varies by income and household size. Weigh dependents — nini keizoku's flat family rate usually beats Kokuho's per-head billing if you're supporting anyone. Remember pension is separate: nini keizoku only continues health insurance, so you must also join kokumin nenkin within 14 days unless you qualify as a Category 3 dependent or start a new job's shakai hoken immediately — leaving Japan for good instead, see the pension lump-sum withdrawal guide. Finally, you're not locked in: since a January 2022 reform you can voluntarily cancel nini keizoku anytime, so if Kokuho turns out cheaper once you have real numbers, you can switch later.

Frequently Asked Questions

Which is cheaper, shakai hoken or kokumin hoken?

It depends on dependents and income, not on which system is "better." Shakai hoken usually wins for households with a non-working spouse or children, since dependents cost nothing extra and pension credit is free for a dependent spouse. For a single person, the gap is often smaller — sometimes Kokuho is cheaper, especially in a low-income year. Get real numbers from HR and your city/ward office rather than assuming.

What happens to my insurance when I quit my job?

Your shakai hoken ends on your last day. You then have 14 days to arrange new coverage: continue your old plan via nini keizoku (apply within 20 days), switch to Kokuho, or become a dependent on a family member's shakai hoken. You must also join kokumin nenkin for pension within 14 days unless you become a Category 3 dependent or start a new job immediately.

Is nini keizoku always the best choice after quitting?

No. It's usually strongest with dependents, since they stay covered free. For a single person, or if income is about to drop a lot, a Kokuho quote can come out lower — nini keizoku premiums are fixed at your former salary level for up to two years. Compare actual numbers before the 20-day deadline.

Do freelancers ever qualify for shakai hoken?

Generally no — shakai hoken is tied to being someone's employee. A sole proprietor with no employees defaults to Kokuho plus kokumin nenkin. (A sole proprietor who incorporates and pays themselves a salary as an employee of their own company is a different, more complex case — get advice if considering it.)

How do part-time hours affect which system I'm in?

Working 20+ hours a week for an employer above the applicable size threshold increasingly pulls you into that employer's own shakai hoken rather than staying a dependent or paying into Kokuho yourself. From October 2026, the wage test for this is removed, so hours — not pay — becomes the main trigger.

If I'm on Kokuho, do I still have to pay kokumin nenkin separately?

Yes. They're two separate systems with two separate bills — Kokuho covers health only, and kokumin nenkin (currently ¥17,920/month for FY2026, regardless of income) has to be enrolled and paid on top.

Does Kokuho ever pay sickness or maternity leave allowance?

Almost never in practice. Municipalities can legally offer a discretionary sickness allowance, but essentially none pay it for ordinary illness, and Kokuho never pays a maternity leave allowance (it does pay the same one-time childbirth lump-sum as shakai hoken). If losing income during illness or leave is a real risk as a freelancer, private income-protection insurance is worth covering that gap.

Sources

• Japan Pension Service (日本年金機構) — Employees' Pension Insurance premium rate: 18.3% total, 9.15%/9.15% employer-employee split, unchanged since September 2017: https://www.nenkin.go.jp/service/kounen/hokenryo/hoshu/20150515-01.html
• Japan Pension Service (日本年金機構) — National Pension (kokumin nenkin) monthly premium for FY2026 (Reiwa 8): ¥17,920/month: https://www.nenkin.go.jp/service/kokunen/hokenryo/hokenryo.html
• Japan Health Insurance Association / Kyokai Kenpo (全国健康保険協会) — FY2026 (Reiwa 8) nationwide average premium rate 9.90%, by-prefecture rate table: https://www.kyoukaikenpo.or.jp/about/business/insurance_rate/premium_prefectures/r08/index.html
• Kyokai Kenpo — Voluntary continued insurance (nini keizoku) rules: application within 20 days, 2+ months prior coverage required, up to 2 years, voluntary cancellation since Jan 2022: https://www.kyoukaikenpo.or.jp/g3/sb3270/
• Kyokai Kenpo — FY2026 voluntary continued insurance standard monthly remuneration ceiling (¥320,000): https://www.kyoukaikenpo.or.jp/news/r07_dec/1259.html
• Ministry of Health, Labour and Welfare (厚生労働省) — Social insurance coverage expansion portal (weekly hours / employer size / wage requirement phase-out): https://www.mhlw.go.jp/tekiyoukakudai/jugyouin/taisho/
• Ministry of Health, Labour and Welfare (厚生労働省) — Income-threshold ("wall") reform page, April 2026 dependent-income test change: https://www.mhlw.go.jp/stf/taiou_001_00002.html
• House of Representatives (衆議院) official Q&A record — municipal Kokuho sickness allowance is discretionary and largely unimplemented for ordinary illness: https://www.shugiin.go.jp/internet/itdb_shitsumon.nsf/html/shitsumon/a210044.htm

Related guides

• National Health Insurance (Kokuho) complete guide — full enrollment, premium, and 2027 visa-payment-link details
• Health insurance and pension enrollment for newcomers — first-time registration paperwork
• High-cost medical expense benefit — the monthly cap that applies under both systems
• National pension exemption and reduction guide — if kokumin nenkin is genuinely unaffordable
• Pension lump-sum withdrawal payment guide — for pension contributions if you leave Japan for good
• Quitting a job in Japan: taishoku daiko guide — the resignation process itself
• Starting a sole proprietorship in Japan — registration steps for freelancers
• How to read a Japanese payslip — see exactly how shakai hoken deductions appear on your pay stub

Last updated: July 2026