NHI for Dependents and Family Coverage

NHI family coverage Japan starts from one structural fact: National Health Insurance enrolls households, not individuals.¹² Your ward office sends one premium notice to your household, and every member without employer insurance adds to that bill.³⁴

Confirm current details with official sources

Procedures, fees, and requirements can change. Confirm current details at your municipal ward or city office.

Overview

Japan assigns your insurance track by status, not by choice.¹ Company employees enter through their employer, and almost everyone else enters through the municipality.¹ A household can straddle both tracks at once, with one spouse on employer insurance and the rest on municipal insurance.¹⁵

This article maps that mixed household: who counts in the municipal headcount, how headcount moves the premium, when a member instead rides free as an employer-insurance dependent, and which counter to visit when the mix changes.¹⁵

Who this article is for

This guide is for NHI-enrolled households and mixed households where some members hold employer insurance and others hold NHI.¹⁵ It covers self-employed, freelance, student, unemployed, and retiree households, plus families where a working spouse holds employer insurance while children or a partner hold NHI.¹

If everyone in your home is on employer insurance with no municipal members, you do not have an NHI household bill to manage.¹ If no one holds employer insurance, the whole household sits inside the municipal count described below.²

How NHI Covers a Household, Not an Individual

National Health Insurance is the municipal safety net for residents outside employer coverage.¹ Enrollment is conducted per household, and the premium or tax is levied on each household rather than on each person separately.²

The statute puts the paperwork duty on the householder: the 世帯主 (setainushi, "head of household") notifies the municipality when any member gains or loses eligibility and requests proof of coverage for household members.⁶ That householder framing is why the bill follows the home, not the patient.

The head of household billing rule

The premium notice goes to the head of household as recorded in the resident register.³² Shinjuku sends its annual notice to the head of each household in mid-June.³ Yokohama recalculates and re-notifies whenever the enrolled-member count or income changes.⁷

One notice covers the whole home

Expect a single bill even when three or four members are enrolled. The notice lists the household total, and the head pays it in one payment flow.³⁷

The duty survives even when the head is not a municipal member. Ota and Honjo English guides state it directly: the head pays the NHI tax when any household member is insured, even if the head is not.²⁸ Practitioner guides call this the 擬制世帯主 (gisei setainushi, "deemed head of household") case, typically a head on employer insurance whose partner or children hold NHI.¹

Who stays out of the NHI household count

Members on employer insurance are not counted in the municipal headcount, because the statute excludes Health Insurance Act insured persons and their dependents from municipal coverage.⁶¹⁵ Neither are residents who have moved to the age 75 plus late-elderly track or who receive public assistance.¹² A family member certified as an employer-insurance dependent stays out of NHI entirely.¹⁵

Short-stay visitors and diplomatic visa holders are not eligible for NHI at all.¹ Everyone else with a stay of three months or more belongs on one track or the other.¹⁹

The diagram below shows how a household sorts each member at a glance.

How Household Size Changes the Premium

Your municipality reprices the household every June from two inputs: how many members are enrolled and what the household earned last year.⁷ There is no national NHI rate, so the same income produces different bills in different cities.¹⁹

Each premium portion combines an income-based amount with a per-capita amount, and the per-capita part is calculated from the number of NHI enrollees.⁴ Yokohama confirms the same shape: enrollee count plus previous-year income, with an extra long-term-care layer for ages 40 to under 65.⁷ Figures below are current as municipal publications state them, so confirm exact rates with your ward office.

The per-capita piece per enrolled member

The premium has three categories. The medical portion and the late-stage elderly support portion apply to every enrolled member, while the long-term-care portion applies only to members aged 40 to 64 (as of 2026-02; confirm current figures with your municipal ward office).⁴¹

Practitioner guides describe typical per-capita levels of about 20,000 to 50,000 yen per person per year for the medical portion alone (as of 2026-02).¹ Some municipalities add a flat per-household levy on top of the per-person amounts, while Tokyo's 23 special wards use an income plus per-capita system with no per-household component (as of 2026-02).¹

Portion	Who it applies to	Annual cap (FY2025 reference)
Medical	Every NHI member	690,000 yen (as of 2026-02)1
Late-stage elderly support	Every NHI member	240,000 yen (as of 2026-02)1
Long-term care	Members aged 40 to 64	170,000 yen (as of 2026-02)1

The combined annual cap across all three portions is 1,060,000 yen (as of 2026-02).¹ A household never pays above that ceiling no matter how large the family grows.

Preschool children cost half the per-capita amount

Since April 2022, children under 6 receive a 50 percent reduction on per-capita levies regardless of household income, applied on top of any income-tested reduction (as of 2026-02).¹ The discount lowers the per-child add-on but does not make children free.

Income piece vs headcount piece

The income levy starts from the previous year's total income minus a 430,000 yen basic deduction, multiplied by the municipality's rate (as of 2026-02; confirm current figures with your municipal ward office).¹ With no prior-year Japan income, the income piece is zero and the household pays only the per-capita floor.¹

Typical municipal medical-portion income rates run about 6 to 9 percent depending on the municipality (as of 2026-02).¹ Low household income triggers automatic statutory reductions of 70, 50, or 20 percent on the per-capita and per-household parts, but only when the household has declared its income.¹

Income follows money while headcount follows people. A pay rise moves the income piece, while a birth or a teenager leaving for university moves the headcount piece and triggers a recalculation notice.⁷

The Shakai Hoken Dependent Path That Bypasses NHI

Employer insurance, known as 社会保険 (shakai hoken, "social insurance") or 健康保険 (kenkō hoken, "Employees' Health Insurance"), can cover family members free as dependents.⁵ NHI has no equivalent: every municipal member adds premium.⁵¹ That asymmetry makes the dependent path the single biggest family-cost decision.

Certification belongs to the insurer, not the ward office.⁵¹⁰ The employer forwards the application to its Kyokai Kenpo branch or corporate health-insurance society, which checks relationship, residency in Japan, and income.⁵¹⁰

Dependent certification basics

The relationship test covers spouses (including common-law partners), children, grandchildren, parents, and grandparents, with some relatives qualifying only when they live with the insured worker.⁵ The residency test has applied since April 1, 2020: dependents must in principle hold a Japanese certificate of residence, and medical-stay or sightseeing-stay holders cannot qualify.¹⁰

The income test uses projected annual income. The standard cap is under 1.3 million yen and less than the insured person's income, rising to under 1.8 million yen for members aged 60 or over or with a disability (as of 2025-11; confirm current figures with the employer insurer).⁵¹¹ For ages 19 to 22 excluding a spouse, the cap changed effective October 1, 2025 to under 1.5 million yen (as of 2026-08).¹¹

Applications travel through the employer to the insurer, commonly within about five days of the change depending on the society.⁵¹¹ The employee's own premium follows salary and plan rate rather than family size, so adding a certified dependent does not raise the worker's contribution.⁵

Foreigner-specific case: Dependent-status family on a Shakai Hoken spouse

A spouse or child holding Dependent residence status who lives in Japan and meets the insurer's relationship, residency, and income tests is certified as an employer-insurance dependent.⁵¹⁰ That member does not enroll in NHI at all.⁵

Dependent-status family members with stays of three months or more are NHI-eligible only when they are not covered as employer-insurance dependents.¹⁵ Certification therefore takes precedence: check the dependent path first, and enroll in NHI only for members the insurer will not certify.⁵¹⁰

Confirm non-certification before enrolling in NHI

When both spouses work and one holds NHI, insurers compare incomes and certify family members under the higher earner.¹⁰ If one insurer refuses certification, attach its non-certification notice when applying to the other insurer rather than enrolling the member in NHI by default.¹⁰

Updating the Household Mix at Job or Status Change

Every move between tracks runs through a counter, and the 14-day clock starts on the triggering date.¹² File at the ward NHI section for municipal changes and through HR for employer-insurance dependent changes.¹²¹¹

The flow below shows the two directions for a worker changing jobs.

Starting a job: leaving NHI for employer insurance

Joining a workplace plan ends municipal coverage for that member from the employer-insurance start date.¹² The household files an NHI withdrawal at the ward office within 14 days.¹²

Bring proof of the new coverage, such as the eligibility certificate or My Number portal eligibility screen, plus the previously used municipal proof for every affected household member.¹² Using the old municipal proof after the start date can trigger a repayment demand for medical costs the city covered in the gap.¹²

Leaving a job: rejoining NHI

The day after employer coverage ends, the member rejoins the municipal count.¹²² File the NHI enrollment at the ward office within 14 days with proof of the coverage end date, such as the certificate of loss of eligibility, plus identification like a residence card, passport, or My Number card.¹²

Late filing still enrolls but back-bills premiums from the eligibility date, up to two years retroactively (as of 2026-02).¹⁵ Medical costs incurred while unenrolled stay effectively full-price out of pocket, so file before anyone needs care.¹

Birth, move-in, and move-out updates

A birth, a move into the municipality, and a move between wards or municipalities all trigger notification.¹²² Register a birth at the municipal office within 14 days including the day of birth, then enroll the child either as an employer-insurance dependent through HR or in NHI.⁵¹²

Event	Where to file	Deadline
Start of employer insurance	Ward NHI section, withdrawal12	Within 14 days
End of employer insurance	Ward NHI section, enrollment12	Within 14 days
Birth	Municipal office registration, then HR or NHI counter5	Within 14 days incl. birth day
Move between municipalities	Old office withdrawal plus new office enrollment12	Within 14 days
New employer-insurance dependent	Employer to insurer511	Within about 5 days per society

Moving out ends the old municipality's coverage from the move-out day, and the new municipality reprices the household at its own rates.¹²¹ A head-of-household change or a household split or merger is its own notification item at the ward office.¹²

Good to know

A new baby does not automatically join your NHI

Birth registration and insurance enrollment are two separate filings.⁵¹² The hospital does not notify the insurer for you. Register the birth within 14 days including the birth day, then file the dependent application through HR or the NHI enrollment at the ward counter before the first checkup.⁵

The deemed head still pays even when on employer insurance

Ota and Honjo English guides state the rule plainly: the head pays the NHI tax whenever any household member is insured, regardless of whether the head is insured personally.²⁸ Budget as one home even when paychecks split across two insurance tracks.

Each child adds a per-capita charge with only narrow reductions

NHI has no free-dependent concept, so each enrolled child adds a per-capita levy on top of the household's income piece (as of 2026-02).¹ The broad relief is the under-6 50 percent per-capita cut plus income-tested statutory reductions, which require a filed income declaration to activate (as of 2026-02).¹

A late status-change notice bills retroactively

Missing the 14-day window does not erase the bill.¹⁵ Municipalities back-bill to the eligibility date, up to two years, and care received in the gap stays full-price.¹ File the withdrawal the same week employer coverage starts so the old city stops its clock.¹²

Moving wards resets the calculation at new local rates

Premium math is municipal, so a move reprices an identical household.¹⁷ Tokyo's 23 wards bill income plus per-capita with no per-household levy, while other municipalities may add a flat per-household amount on top (as of 2026-02).¹ Ask the new ward for an estimate before the first notice arrives.

See also

• Medical Subsidies for Children
• Child Benefit (Jidō Teate)
• How Japan's Universal-Coverage System Works
• NHI Premium Calculation
• NHI Enrollment at the Ward Office
• The Dependent (Fuyo) System

References

Footnotes

1. JapanTalkback Editorial (Kantenna series). National Health Insurance (NHI) in Japan for Foreigners, Episode 02 (published 2026-02-21). https://kantenna.com/series/health-insurance-japan-foreigners-complete-guide-series/national-health-insurance-japan-foreigners-nhi-guide ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷ ↩²⁸ ↩²⁹ ↩³⁰ ↩³¹ ↩³² ↩³³ ↩³⁴ ↩³⁵ ↩³⁶ ↩³⁷ ↩³⁸ ↩³⁹

2. City of Ota, National Health Insurance Division. National Health Insurance guide for foreign residents (English PDF; enrollment per household, head-of-household payment duty). https://www.city.ota.gunma.jp/uploaded/attachment/41442.pdf ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

3. City of Shinjuku, Foreign Language Top Page. National Health Insurance Premium Payments Notification (notice sent June 12 to head of each household; FY2026 child and child-rearing support addition). https://www.foreign.city.shinjuku.lg.jp/en/news/260615_2 ↩ ↩² ↩³ ↩⁴

4. City of Shinjuku, Foreign Language Top Page. Health Insurance (National Health Insurance). https://www.foreign.city.shinjuku.lg.jp/en/kurashi/hokenryo/ ↩ ↩² ↩³

5. Japan Handbook, Sarah Williams. Adding Family Members to Your Health Insurance in Japan: Dependent Coverage (2025-11-12). https://japanhandbook.com/adding-family-members-to-your-health-insurance-in-japan-dependent-coverage/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴

6. Japanese Law Translation. National Health Insurance Act (Act No. 192 of 1958, English translation, last version Act No. 28 of 2012). https://www.japaneselawtranslation.go.jp/en/laws/view/2453/en ↩ ↩²

7. City of Yokohama. About National Health Insurance premiums (last updated 2023-03-01). https://www.city.yokohama.lg.jp/lang/residents/en/insurance/default2020030.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

8. City of Honjo. Living Guide for Foreign Residents (English PDF; NHI tax section). https://www.city.honjo.lg.jp/material/files/group/10/eigo.pdf ↩ ↩²

9. Zainichi Life Navi Editorial Team, MRI Co. National Health Insurance for Foreigners in Japan: Enrollment, Premiums and Usage (published 2026-06-04, updated 2026-07-12). https://life.m-ri.co.jp/en/health-insurance.html ↩ ↩²

10. AZSA Health Insurance Society (English). Family membership: dependent certification conditions. https://www.azsa-support.jp/kenpo/eng/member/outline/family_a.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

11. Works Human Intelligence Health Insurance Society (English). Adding a family member: dependent certification standards. https://www.whi-kenpo.jp/eng/situation_12.jsp ↩ ↩² ↩³ ↩⁴ ↩⁵

12. City of Yokohama. Joining and leaving the National Health Insurance scheme. https://www.city.yokohama.lg.jp/lang/residents/en/insurance/kokuhoenglish.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷