Health Insurance Society vs. Kyokai Kenpo

Health Insurance Society vs Kyokai Kenpo is the comparison every newly hired employee in Japan meets in the first week: two administrators running the same Employees' Health Insurance, with your employer deciding which one holds your file.¹² The card in your wallet looks similar either way, but the office that sets your rate and pays your cash benefits is different.

Confirm current details with official sources

Procedures, fees, and requirements can change. Confirm current details at the Japan Health Insurance Association (Kyokai Kenpo) site or the Ministry of Health, Labour and Welfare.

Overview

Employees' Health Insurance covers company employees and their dependents through an administrator called the insurer, as mapped in How Japan's Universal-Coverage System Works.¹ That administrator is either the employer's own 健康保険組合 (kenkō hoken kumiai, "Health Insurance Society") or the 全国健康保険協会 (zenkoku kenkō hoken kyōkai, "Japan Health Insurance Association," Kyokai Kenpo).³¹²

You do not apply to one or the other. Your employer enrolls you, and enrollment follows the firm: a company with its own society puts you there, and a company without one puts you in Kyokai Kenpo.¹²

What the two names refer to

The Health Insurance Society is an employer- or industry-specific body that operates health-insurance business under the Health Insurance Act as a public corporation.¹² Kyokai Kenpo is the nationwide association that performs the same role for everyone else, organized as a headquarters plus 47 prefectural branches.³

Kyokai Kenpo was established on October 1, 2008 under the Health Insurance Act, and it operates with about 2,100 staff.³ Societies are governed by a council of employer and insured representatives, with an executive board carrying out day-to-day operations.¹

The Two Administrators

Societies exist because the law lets groups of employers run coverage themselves once they reach a viable scale. Kyokai Kenpo exists so every other employee still has an administrator even when the employer is small.

Health Insurance Societies for larger employers

A single company with 700 or more insured employees can establish its own society with government approval.¹² Two or more employers can jointly establish one when their combined insured workforce reaches 3,000 or more.¹²

Establishment also needs the consent of at least half of the insured persons and final approval by the Minister of Health, Labour and Welfare.² Societies therefore cluster around larger firms and industry groups, which matches the everyday pattern that big-company employees carry a society card.¹²

About 28 million employees and family members belong to societies (as of 2026-09-07; confirm current enrollment with Kenporen).¹ Premiums are collected monthly from insured persons and their employers, and the society uses that income for its two jobs: paying insurance benefits and running health services.¹

Kyokai Kenpo for firms without their own society

Kyokai Kenpo covers employees whose employers maintain no society, which includes most small and medium firms.³ Each member belongs to the prefectural branch where the employer files, and benefit applications go to that branch.³⁴

Rates differ by prefecture and are revised every year. The Reiwa-8 schedule applies from the March salary (paid in April) for regular members (as of 2026-02; confirm current rates with Kyokai Kenpo).⁵

Prefecture	Health-insurance rate	As of	Notes
Tokyo	9.85%	2026-025	Shared between employer and employee
Kanagawa	9.92%	2026-025	Shared between employer and employee
Osaka	10.13%	2026-025	Shared between employer and employee

The table above covers the health-insurance rate alone. From the April payment onward, a nationwide child-rearing support surcharge of 0.23% is added, and members aged 40 to 64 add a nationwide nursing-care rate of 1.62% (as of 2026-02).⁵

What Is Identical and What Differs

The comparison below separates what the law fixes for everyone from what each administrator decides on its own. The left column never changes with your card issuer; the right column can.

Dimension	Identical nationwide	Differs by administrator
Medical menu at the counter	Same scheduled services and the same patient share (30% in the standard case, insurer pays the rest)1	No difference; a society card buys no separate treatment list
Cash benefits in principle	Sickness allowance and childbirth benefits exist under the same statute46	Filing counter and supplementary top-ups differ
Premium rate	Employer/employee split structure	Kyokai Kenpo sets a prefectural rate yearly; each society sets its own rate52
Health programs	Annual checkup framework	Societies run voluntary programs of their own design; Kyokai Kenpo runs branch programs1

The figures in this section's table carry their currency in the As of column. Kyokai Kenpo rates shown are the Reiwa-8 schedule (as of 2026-02).⁵

The statutory floor both share

At the counter, both administrators work the same way: you pay your share and the insurer settles the rest through the claims-review route.¹ In the standard working-age case that share is 30%, with the insurer covering 70%.¹

Cash benefits follow the same statutory shape on both sides. Sickness allowance supports an employee who misses work for a non-occupational illness or injury, and childbirth coverage combines an absence allowance with a lump-sum payment.⁴⁶

Sickness allowance pays only when four conditions all hold: the rest is for a non-occupational illness or injury, the worker cannot work (judged with the attending physician's view of the actual job), the absence runs at least four days including three consecutive waiting days, and no salary covers the period.⁴ Where salary is paid but lower than the allowance, the difference is paid.⁴ The benefit period totals 1 year and 6 months from the start date, and the daily amount is roughly two-thirds of the daily standard-remuneration base.⁴

Childbirth coverage uses a broad definition of birth: delivery at 85 or more days of gestation, including premature birth, stillbirth, miscarriage, and induced abortion.⁶ The allowance compensates absence around birth, while the lump sum offsets delivery costs.⁶

Supplementary benefits and service options

This is where societies can exceed the floor. A society may set its own premium rate, may set the employee share below half, may pay 付加給付 (fuka kyūfu, "supplementary benefits") that lighten counter or cash burdens beyond the statute, and may run voluntary health programs such as checkup subsidies as employer welfare.²

Societies describe their work as two pillars. Insurance benefits pay medical costs and the sickness, childbirth, and death payments.¹ Health services support prevention and early detection, increasingly tailored per society from checkup and claims data.¹

Kyokai Kenpo's published menu centers on the statutory benefits plus branch-run checkups and health guidance.³ It does not publish a society-style autonomous supplementary layer of its own. The practical result is modest: identical treatment at the counter, with somewhat richer add-ons or services on many society plans.

The card issuer decides where cash claims go

Sickness-allowance applications go to the administering insurer: the society for society members, or the Kyokai Kenpo prefectural branch for Kyokai Kenpo members.⁴ Childbirth-benefit applications follow the same routing.⁶

Which One You End Up In

The rule fits in one sentence: the current employer decides. Join a firm with a society and you enter that society; join a firm without one and you enter Kyokai Kenpo.¹² No separate application chooses the administrator.

This pattern shapes the typical foreign-resident experience described in planning scope: employees of major Japanese employers usually hold a society card, while employees of smaller firms usually hold Kyokai Kenpo coverage. Practitioner sources describe this pattern consistently, but no primary release quantifies foreign residents by administrator, so treat it as the usual case rather than a guarantee.

How to tell from your card and enrollment documents

Since December 2, 2024, newly enrolled members receive a notice of eligibility information rather than a standalone card, and clinic visits use My Number insurance linkage or an eligibility certificate.⁷ The insurer identity sits in that qualification record, not in a logo you memorize.

Legacy employer-issued health-insurance cards fully expired on December 2, 2025, and transitional acceptance for unaware holders ended on July 31, 2026 (as of 2026-09-07).⁷ If you still carry an old card, it no longer proves coverage.

Your employer files the acquisition notice with your My Number to the Japan Pension Service within 5 days of the qualifying event.⁷ New hires who need care before the linkage is visible should ask the employer which insurer holds the file, then present the notice or certificate the insurer issued.

Changing employers and administrator switches

Coverage follows the current job. Leaving a society employer ends that society's coverage, and joining a Kyokai Kenpo employer starts Kyokai Kenpo coverage, with the reverse true in the opposite move.¹²

The full loss-and-acquisition procedure at job change, including the 20-day continuation option after resignation, belongs to dedicated follow-up articles. For this comparison the point is only routing: after a move, cash-benefit and certificate requests go to the new administrator, not the old one.⁴

Good to know

Supplementary benefits are modest extras, not a different medical system

A society card does not unlock different doctors or different covered treatments. The counter math and the treated menu are the same, and the society edge is add-on payments or services around the edges.¹² Choose a job for the job, not for the insurer name.

Premium rates move by administrator and year

Kyokai Kenpo rates differ by prefecture and change every year, so a Tokyo figure never prices Osaka and last year's table never prices this year (as of 2026-02).⁵ Society rates are set per society and differ again.² Budget from your own branch or society notice for the current year.

Confirm which insurer holds your file before any cash-benefit claim

Sickness-allowance and childbirth-benefit forms carry physician and employer sections, and they go to the administering insurer.⁴⁶ Filing to the wrong counter costs weeks. Check the qualification notice first, then download that insurer's form.

See also

• How Japan's Universal-Coverage System Works
• What Insurance Doesn't Cover
• Shakai Hoken Overview
• The Dependent (Fuyo) System
• Maternity and Childbirth Allowances
• Continuation After Resignation: Nin-i Keizoku

References

Footnotes

1. 健康保険組合連合会 (Kenporen). 「健康保険の基礎知識 第8回 知ってる? 健保組合の仕事」. https://www.kenporen.com/health-insurance/basic/08.shtml ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰

2. 健康保険組合連合会 (Kenporen). 「健保組合の設立について」. https://www.kenporen.com/join-establishment/kumiai_setsuritsu/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴

3. 全国健康保険協会 (Kyokai Kenpo). 「全国健康保険協会の概要」. https://www.kyoukaikenpo.or.jp/about/about_kenpo/outline/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

4. 全国健康保険協会 (Kyokai Kenpo). 「傷病手当金」. https://www.kyoukaikenpo.or.jp/benefit/injury_and_sickness_allowance/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

5. 全国健康保険協会 (Kyokai Kenpo). 「令和8年度の協会けんぽの保険料率は3月分（4月納付分）から改定されます」 (prefectural rate table). https://www.kyoukaikenpo.or.jp/about/business/insurance_rate/rate_prefectures/r08/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

6. 全国健康保険協会 (Kyokai Kenpo). 「出産育児一時金・出産手当金」. https://www.kyoukaikenpo.or.jp/benefit/childbirth/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

7. 全国健康保険協会 (Kyokai Kenpo). 「マイナ保険証等での受診」. https://www.kyoukaikenpo.or.jp/benefit/mynumber_insurance_card/001/ ↩ ↩² ↩³