Shakai hoken vs kokumin kenko hoken: which insurance are you in

If a company employs you full-time, or part-time for 20 or more hours a week at a workplace of 51 or more employees and you are not a student, you belong in shakai hoken (社会保険): workplace health insurance plus employees’ pension. Everyone else uses the city’s National Health Insurance (国民健康保険, often called kokuho). As of October 2026, an employee in Tokyo paid about ¥300,000 a month pays ¥42,570 a month for health, pension and the new child support levy, and the employer pays the same again.

What is shakai hoken, and how is it different from kokumin kenko hoken?

In this guide, shakai hoken means the two plans you join through work: health insurance (健康保険) and employees’ pension (厚生年金). National Health Insurance (国民健康保険) is the city plan for people who have no workplace plan. Nationality doesn’t decide which you use. Your work does. The Japan Pension Service enrollment page lists no nationality condition.

Our guide to National Health Insurance for foreigners covers its costs and reductions in detail. This page helps you decide which one applies.

Which insurance am I in?

Three questions, in order:

1. Do you work for a company or office as an employee? Employees under age 70 of a workplace that regularly employs staff are enrolled in employees’ pension, and the employer files the paperwork. Health insurance goes with it.
2. Are you part-time? You are enrolled if your scheduled hours and days are at least 3/4 of a regular employee’s. Below that, you are still enrolled if you work 20 or more scheduled hours a week, are not a student, and are expected to work more than 2 months.
3. Neither of these? Freelancers, the self-employed, the unemployed, most students and people between jobs use National Health Insurance.

Does the size of my employer matter?

For part-timers on the 20-hour rule, yes. As of October 2026 it applies at workplaces with 51 or more employees. The ministry’s schedule lowers this to 36 to 50 employees in October 2027, 21 to 35 in October 2029, 11 to 20 in October 2032 and 10 or fewer in October 2035. The count is people already eligible for employees’ pension at that workplace, not everyone on the roster.

What if my hours change?

If you have no fixed weekly hours, the ministry divides your scheduled monthly hours by 52/12. If your actual hours reach 20 or more a week for two months in a row and are expected to continue, you are covered from the third month.

Do foreign students count?

Students are generally excluded from the part-timer rule. The ministry names some exceptions: students on leave, and those in part-time (定時制) or correspondence (通信制) programs. Check your own school type. For work limits on a student status, see student visa work permits.

How much does shakai hoken cost?

Your premium is a percentage of your standard monthly remuneration (標準報酬月額), a band that your pay falls into. The employer pays half. The 協会けんぽ (Japan Health Insurance Association) table for Tokyo, FY2026, lists these rates:

Pay of ¥290,000 to under ¥310,000 falls in the ¥300,000 band. Under 40, your half totals ¥42,570 a month. At ages 40 to 64, it is ¥45,000. Other prefectures have a different health rate, and company health societies (健保組合) may differ from the 協会けんぽ table. Pension bands start at ¥88,000.

The pension part is the same 18.3% for everyone, and the employer pays half. For a full take-home breakdown, see take-home pay in Japan. If you leave Japan, see the pension lump-sum refund.

Can my family be on my shakai hoken?

Yes, as dependents (被扶養者). They pay no premium. The Japan Pension Service sets these tests:

• They live in Japan and are mainly supported by you. Since April 2020, they need an address in Japan, judged by the resident record (住民票).
• Annual income is under ¥1.3 million (about ¥108,333 a month). The limit is ¥1.8 million for age 60 and over or disabled, and ¥1.5 million for ages 19 to 22 since 1 October 2025.
• If you live together, their income is also under half of yours. If apart, it is under the amount you send.
• Spouse, children and parents don’t have to live with you. Other relatives within three degrees do.
• Non-Japanese on Designated Activities (特定活動) for medical treatment or long-term tourism don’t qualify.

Students abroad are an exception to the address rule. Bring a visa, student ID or enrollment certificate. Documents in a foreign language need a Japanese translation signed by the translator.

What changes when I change jobs?

The two plans don’t switch on their own. When you leave a job without a new one, tell the city office and join National Health Insurance within 14 days. If you join late, you still owe premiums back to the date you became eligible.

Voluntary continuation (任意継続) keeps your 協会けんぽ plan for up to 2 years. You need at least 2 months of continuous coverage before you leave, and you apply within 20 days of the day after you leave. The premium is twice what was deducted from your pay, because you now pay the employer’s half, and it is capped at the amount for ¥320,000 of standard pay. It ends early if you join another plan or miss a payment. It can be cheaper or dearer than National Health Insurance, which depends on your last year’s income, so compare both at the counter.

What to bring and say at the counter

Bring your residence card (在留カード), My Number (マイナンバー), your ID and the loss-of-eligibility proof from your employer. For a health insurance card, see My Number health insurance card. We found no official note on English support at pension offices or 協会けんぽ branches, so bring a Japanese-speaking friend or ask the city’s foreign-resident desk.

This page is general information. For your own case, ask the city counter, your employer’s HR, or a licensed social insurance specialist (社会保険労務士).

More guides

• National Health Insurance for foreigners
• The Japanese pension for foreigners
• Take-home pay in Japan
• Pension refund when you leave Japan
• Unemployment benefits for foreigners