Leaving a job in Japan: how to switch health insurance
Your former employer's health coverage normally ends after your last official employment day. From the next day, you need coverage through a new employer, voluntary continuation, National Health Insurance, or a family member's plan.
When you leave a job in Japan, your old employer's health insurance does not automatically continue until you find another position. In principle, that eligibility ends on the day after your official leaving date. You need to move to suitable coverage even if the gap between jobs is only a few days.
There are 4 common routes: join the new employer's plan; voluntarily continue the old plan under 任意継続; enroll in municipal 国民健康保険 (National Health Insurance); or become a 被扶養者, a dependent under an eligible family member's employee insurance. No choice is always cheapest. Compare premiums, the expected employment gap, household size, and income conditions.
Quick decision table after leaving a job
Situation | Main route | Where to apply | Key deadline |
|---|---|---|---|
New employer covers you from the next day | New employer's health insurance | New employer | Confirm eligibility start date |
A gap before the next job, or becoming self-employed | Compare 任意継続 and 国民健康保険 | Former insurer or municipal office | 20 days for 任意継続; 14 days for 国民健康保険 |
Spouse or eligible family member has employee insurance | Apply as 被扶養者 if eligible | Insured family member's employer | Ask and submit promptly; each insurer reviews eligibility |
Still deciding near the deadline | Request premium estimates and prepare both sets of papers | Insurer and municipality | Do not miss the 20-day 任意継続 deadline |
What matters is not merely whether an application has been submitted, but the date new eligibility begins. If employment ends on August 31 and new coverage starts September 1, there is normally no gap. If it starts September 10, you must still address September 1-9.
When does the old employer's insurance stop?
Old eligibility lasts through the official leaving date. If that date is August 31, you cannot receive care under that eligibility from September 1, even if My Number has not updated or a 資格確認書 (eligibility confirmation document) shows a later printed expiry.
Check the official 退職日, not merely the last day you physically attended work.
Do not use マイナ保険証 under the former eligibility after it ends.
Return any still-valid 資格確認書 as instructed; expired documents and information-only notices may be handled differently.
Remind the employer to process every person who was your dependent.
Request a 健康保険資格喪失証明書, certificate of loss of health-insurance eligibility, promptly.
If you use the former eligibility by mistake, the insurer may demand repayment of the portion it paid to the provider. A clinic being able to read the card does not prove that the legal eligibility remains valid.
4 ways to switch health insurance
1. Join the new employer's insurance
This is usually simplest when there is no gap and the new work is covered by 社会保険. The employer registers you, but you should verify the effective date.
Tell HR that eligibility under the former employer has ended.
Provide My Number and the documents requested by the new employer.
Ask for the exact 健康保険資格取得日, eligibility acquisition date.
Submit a 被扶養者 application for every family dependent.
If you temporarily joined 国民健康保険, withdraw from it yourself after new eligibility begins.
Do not assume the new company will cancel municipal insurance for you. The systems do not always complete the switch automatically. Without a withdrawal notice, municipal premium bills may continue and later require adjustment.
2. Voluntarily continue the former plan through 任意継続
Under 協会けんぽ, you can apply for 健康保険任意継続 if you were continuously insured for at least 2 months before losing eligibility and the application reaches the responsible office within 20 days from the loss date. When day 20 is a weekend or holiday, the next-business-day rule may apply. A mailed form must arrive by the deadline, so early mail or electronic filing is safer.
The filing office is usually the 協会けんぽ branch for the prefecture where you live.
If the old coverage was a company-specific 健康保険組合, ask that fund directly; its forms and calculations may differ.
Coverage normally lasts up to 2 years, but can end earlier after entering a new employee plan, missing a premium deadline, requesting termination, or another statutory event.
The employer contribution disappears, so your personal payment often rises substantially.
協会けんぽ generally calculates the premium from the standard monthly remuneration at departure, subject to a ceiling; it is not always exactly twice the payroll deduction.
An important advantage is that eligible dependents normally do not create a separate per-person premium. This can make 任意継続 worth comparing for a larger household. However, 傷病手当金 and 出産手当金 do not simply continue in full because you selected 任意継続. Only certain people meeting continuation requirements from employment may remain eligible.
3. Enroll in 国民健康保険
If you do not enter another employee plan and are not an eligible dependent, you will generally enroll in 国民健康保険 at the municipality where your residence is registered. Japan's Ministry of Health, Labour and Welfare says enrollment and withdrawal changes must be reported within 14 days.
Apply at the 国民健康保険 section of your ward office or city hall.
Depending on the municipality, filing may be available at the counter, by post, or online.
Eligibility normally dates back to the day after employee insurance ended, not the filing day.
Premiums usually reflect prior-year income, enrolled household members, and local rules.
Unlike employee insurance, 国民健康保険 has no free-dependent category; each covered person is included in the household calculation.
Late filing does not remove the obligation. The municipality may assess premiums retroactively from the eligibility date within applicable legal limits. Before registration is completed, you may temporarily need to pay the entire medical bill and later request reimbursement of the insured portion.
4. Become a family member's 被扶養者
If a spouse or another permitted relative has employee insurance, you may apply as a 被扶養者. An approved dependent pays no separate health-insurance premium, but unemployment alone does not automatically establish eligibility.
Contact HR at the insured family member's employer.
Confirm the required family relationship, co-residence, or financial support evidence.
Submit proof of current and expected income, not only last year's income.
Declare unemployment benefits and other income when the insurer requires them.
Wait for confirmation of the effective date instead of assuming approval.
Income thresholds and evidence have exceptions based on age, disability, relationship, living arrangements, and the insurer's rules. Do not decide eligibility from one income number in this article. Obtain the exact checklist from the family member's employer.
Comparing costs: do not rely on the old payslip
Point | 任意継続 | 国民健康保険 | 被扶養者 |
|---|---|---|---|
Main basis | Standard remuneration at departure and insurer rules | Prior-year income, household members, and local rules | Must meet dependency requirements |
Employer contribution | None | None | No separate premium charged to the dependent |
Effect of family size | Eligible dependents usually add no separate premium | More enrolled members can increase the household premium | Every person needs approval |
Possible relief | Depends on insurer mechanisms | Reductions or exemptions may apply | Not a cost-saving route unless eligible |
Request actual estimates before choosing. For 国民健康保険, ask the municipality using prior-year income and the number of people enrolling. For 任意継続, ask the former insurer for the monthly premium and payment schedule. Compare the same time period and include the whole family.
People who lose work through bankruptcy, dismissal, or certain justified reasons may qualify for a 国民健康保険 reduction. Edogawa, for example, calculates the eligible person's prior-year employment income at 30% for this purpose. An application and an eligible separation-reason code on the 雇用保険受給資格者証 or 雇用保険受給資格通知 are required; this is not automatic for everyone who resigns.
Documents to request before leaving
Document or information | Purpose | Issuer or source |
|---|---|---|
Official 退職日 | Determines when former insurance ends | Former employer |
健康保険資格喪失証明書 | Proves loss date for 国民健康保険 enrollment | Employer or insurer |
退職証明書 or 離職票 | May be accepted by some municipalities in limited cases | Employer/Hello Work |
My Number and identity document | Verifies filer and household members | Prepare personally |
Income, relationship, and support evidence | Used for 被扶養者 review | Individual and relevant authorities |
雇用保険受給資格者証 or 受給資格通知 | Used to assess involuntary-unemployment relief | Hello Work |
Requirements differ by municipality. Edogawa requests proof showing the insurance loss date; a person without dependents may use a 退職証明書 or 離職票 in some filing routes. Counter applications may also need My Number evidence, identification, and bank details for premium payments.
Step-by-step process to avoid a gap
Confirm 退職日 and the eligibility loss date with the former employer.
Ask the new employer for the exact insurance start date.
If there is a gap, immediately check family-dependent eligibility.
At the same time, obtain premium estimates for 任意継続 and 国民健康保険.
Decide whether to file for 任意継続 before 20 days expire.
If choosing 国民健康保険, report within 14 days and supply missing evidence promptly.
Check マイナポータル or a confirmation document for the new status.
If care is needed during transition, explain the situation and retain receipts.
On starting another job, withdraw from 国民健康保険 or end 任意継続 correctly.
Handle pension separately; changing health insurance does not complete pension changes.
If the 健康保険資格喪失証明書 is delayed, do not silently wait beyond the deadline. Ask the municipality and insurer whether you can file first and supplement later. Edogawa states that filing after 14 days remains possible when the certificate was delayed, but the notice should be made promptly once documents are ready. Other municipalities may handle this differently.
If you need medical care during the transition
Administrative processing does not authorize continued use of the former eligibility. Tell reception that you recently left a job and are switching insurance.
Do not present the old 資格確認書 as valid.
Bring your My Number card, identification, and any new-eligibility documents.
Ask whether insurance details can be supplied later within the same month.
If paying 100%, keep the 領収書 and itemized statement for a reimbursement inquiry.
Confirm which new insurer or relevant body receives the reimbursement claim.
Whether the provider can adjust payment and which reimbursement papers are required depend on timing, the provider, and confirmed eligibility. Keep the receipts even after My Number updates.
Do not forget 国民年金 after leaving
Health insurance and pension are separate procedures. After leaving and before another covered job, people aged 20 to under 60 generally need to consider switching from 厚生年金 to 国民年金第1号. A person qualifying as a dependent of a spouse enrolled in 厚生年金 may become 国民年金第3号, usually through the spouse's employer.
Choosing 任意継続 does not continue 厚生年金.
Joining 国民健康保険 does not automatically enroll you in 国民年金.
Health-insurance dependency does not always mean 第3号 eligibility, especially for a relative other than a spouse.
If payment is difficult, ask about exemption, reduction, or postponement instead of ignoring notices.
Common mistakes
Using former employer coverage because My Number has not updated.
Waiting for 離職票 and missing the 20-day 任意継続 deadline.
Assuming a mid-month resignation leaves no insurance obligation.
Comparing 任意継続 with the payslip deduction while forgetting the old employer share.
Comparing only your own premium and ignoring family members.
Joining 国民健康保険 but failing to withdraw after employee coverage starts.
Assuming late filing means premiums begin only on the filing date.
Believing the health-insurance switch also completed the pension switch.
Frequently asked questions
I leave Friday and start a new job Monday. Is the weekend uncovered?
Possibly. It depends on the old eligibility loss date and the new eligibility acquisition date, not simply attendance dates. Ask both employers for exact dates. If a gap exists, ask the competent authority how to cover it.
Can I choose 国民健康保険 and later change to 任意継続?
Do not rely on changing later. 任意継続 has a strict 20-day application deadline. Request estimates and decide before it expires.
Which option is definitely cheaper?
There is no universal answer. Results differ for a single person, someone with low prior-year income, a large dependent household, or a person eligible for relief. Estimates from the former insurer and municipality are the reliable comparison.
If I leave Japan for Vietnam immediately, must I switch?
It depends on your departure date, whether you filed a move-out notice and ended resident registration, and your actual residence status. Ask the municipality about 転出届, 国民健康保険, and 国民年金 before departure.
What if the company has not issued the loss certificate?
Request the 健康保険資格喪失証明書 and ask the municipality whether it accepts a 退職証明書, 離職票, or later supplementation. Accepted substitutes and filing channels vary.
Do I need to do anything if I change jobs immediately?
Yes. Return any valid old eligibility document, verify the new start date, file for dependents, and address any gap. If you entered 国民健康保険, notify withdrawal after new coverage begins.
Final checklist
Confirm the leaving date and eligibility loss date.
Stop using former insurance from the next day.
Request the loss-of-eligibility certificate.
Compare all 4 routes for your household.
Record the separate 14-day and 20-day deadlines.
Request estimates instead of guessing from a payslip.
Keep receipts for care during transition.
Withdraw from temporary coverage when new coverage starts.
Complete the separate 国民年金 procedure.
Rules and documents can differ by insurer and municipality. Before filing, check the official page of the authority handling your case.