National Health Insurance after you move: joining in Kumamoto City, Kikuyo Town and Ozu Town (2026)

This page is general information from official sources. It is not legal or financial advice, and it cannot tell you whether you must join. For your own case, ask the National Health Insurance counter of your city or town.

If you have just moved to Kumamoto City, Kikuyo Town or Ozu Town and your job does not give you health insurance, you will probably need National Health Insurance. This guide compares how to join in the three places: who joins, where to apply, the deadline, what to bring, and what happens if you apply late.

Item	Kumamoto City	Kikuyo Town	Ozu Town
Where	Ward or branch office, or by post	Town Office	Town Office
Deadline	14 days	Not stated	14 days
You pay	Premiums	A tax	A tax
Charged back	Up to 2 years	Not stated	Up to 3 years

1. Do I need to join?

Official rule (Japan)

National Health Insurance (国民健康保険, kokumin kenko hoken, often called kokuho) is public health insurance run by each city and town together with the prefecture. You join it in the city or town where you are registered as a resident.

Kumamoto City and Kikuyo Town give the same list. If you are registered as a resident and none of these apply to you, you must join:

• You are in a workplace health insurance plan, or you are a dependant of someone in one.
• You are in the Late-Stage Elderly Medical Care System (generally age 75 and over).
• You stayed in your former workplace plan after leaving the job (voluntary continuation, 任意継続).
• You receive public assistance (生活保護).
• You are a foreign national whose status of residence is Designated Activities for medical treatment, or for sightseeing and recreation.

If you are not sure which group you are in, ask your employer or the counter. This page cannot decide it for you.

Ozu Town lists the times when you must notify the town that you are joining. They include moving in from another city or town, losing workplace insurance (for example, after leaving a job), no longer being a dependant, the birth of a child, and the end of public assistance. Ozu Town says the switch between plans does not happen automatically.

2. Kumamoto City

Kumamoto City

2.1 Where and when to apply

You can apply at the Citizens’ Affairs Section (区民課) of any of the five ward offices (Chuo, Higashi, Nishi, Minami, Kita), or at any of the seven general branch offices (総合出張所). You can also print the form from the city’s page and send it by post, or ask someone to go for you with a letter of proxy.

Apply within 14 days of the day you moved in, or of the day you lost your workplace insurance. Your coverage starts on that day, not on the day you apply, and premiums are charged back to that month for up to two years. Premiums are calculated by fiscal year, from the month you join until March.

2.2 What to bring

The documents depend on why you are joining. The city lists these:

• Moved in from another city or town in Japan: proof of your income for last year, something that shows your My Number, and your bank cash card.
• Left a workplace plan or stopped being a dependant: a certificate of loss of coverage (健康保険資格喪失証明書) that shows the date for everyone joining, something that shows your My Number, and your bank cash card.
• Foreign nationals: your residence card or passport, something that shows your My Number, and, only if your status of residence is Designated Activities, your designation document (指定書).

With the bank cash card, you can set up direct debit of your premiums at the counter.

2.3 Getting your insurance document

You receive a certificate of eligibility (資格確認書, shikaku kakuninsho) or a notice of your eligibility information (資格情報のお知らせ). You can get it on the same day only at a ward office or general branch office, not at a community center (まちづくりセンター). Show photo ID issued by a public office, such as a passport or My Number Card. Without it, the document is mailed to your registered address.

A Kumamoto City video (in Japanese) about using the My Number Card as your health insurance card, from the city’s official YouTube channel:

National Health Insurance phone lines at the ward offices’ Citizens’ Affairs Sections: Chuo 096-328-2278, Higashi 096-367-9125, Nishi 096-329-1198, Minami 096-357-4128, Kita 096-272-6905. Ward office counters are open on weekdays from 9:00 to 16:30. Addresses and maps are in Registering your address in Kumamoto City, Kikuyo Town and Ozu Town.

Official page on joining and leaving (Japanese)

3. Kikuyo Town

Kikuyo Town

Apply at the Health and Insurance Division (健康・保険課) of Kikuyo Town Office. This is not the same counter as the Municipal Division (町民課), where you register your address. Register your address first; the town’s English guide says National Health Insurance is for people who are not in a workplace plan.

In Kikuyo Town, you pay for the insurance as a tax, National Health Insurance tax (国民健康保険税). The household head is the taxpayer.

3.1 How to join

1. Register your address at the Municipal Division. If you hold a residence card, the town currently asks you to do this at the main Town Office.
2. Prepare your documents. If you moved from another city or town in Japan, bring the moving-out certificate. If you left a workplace plan, bring a certificate that shows the date your coverage ended; the town has its own form for this. In each case, bring ID and your My Number Card.
3. Go to the Health and Insurance Division. Forms are at the counter, and you can fill them in there.
4. Bring a letter of proxy if someone else goes. The town asks for one when a person from another household applies for you.

The town’s English Guide to Living in Kikuyo Town (2024) explains the three public health insurance plans. For help in your language, the Consultation Counter for Foreign Residents on the ground floor of the Town Office has a Chinese interpreter on weekdays and telephone interpreting in 21 languages.

Address: 2800 Kubota, Kikuyo-machi, Kikuchi-gun, Kumamoto 869-1192 · Google Maps
Phone: 096-232-4912 (Health and Insurance Division)
Official National Health Insurance page (Japanese)

4. Ozu Town

Ozu Town

If you are moving in, first file your moving-in notice at the Resident Affairs Division (住民課). Ozu Town says you can join National Health Insurance after that, at the Health Insurance Division (健康保険課) in the same building. Notify the town within 14 days of the change.

4.1 What to bring

• Moving in from another city or town: the moving-out certificate from your previous office.
• After leaving a job: a certificate of loss of coverage (資格喪失証明書) or a separation notice (離職票) that shows the date.
• No longer a dependant: a certificate that shows you are no longer a dependant.

Someone from a different household can apply for you with a letter of proxy; the form is on the town’s page.

4.2 How the tax is charged

Ozu Town charges the insurance as National Health Insurance tax (国民健康保険税). It is charged from the month you became eligible, such as the month you moved in, and the town can go back up to three years. When you join during the year, the tax is counted from that month until March. As a rule, the town sends the tax notice in the month after you notify, and a year’s tax is split into eight payments.

The amount depends on your household’s income and size. The town’s tax estimate page has an Excel sheet for fiscal 2026; the Tax Division (税務課) gives the actual amount.

For help in your language, the Foreign Residents Consultation Desk at the general information counter on the 1st floor has interpreters on set days; English is on Wednesdays. Check the monthly calendar on the desk’s page.

Address: 1233 Oaza Ozu, Ozu-machi, Kikuchi-gun, Kumamoto 869-1292 · Google Maps
Phone: 096-293-3114 (Health Insurance Division), 096-293-3117 (Tax Division)
Official page on when to notify (Japanese)

5. When you leave National Health Insurance

If you later join a workplace plan or move out, you must tell the city or town so that you leave National Health Insurance. Kumamoto City asks you to do this within 14 days. All three offer a way to do it without visiting when you have joined a workplace plan:

• Kumamoto City: online application, or by post to your ward office.
• Kikuyo Town: an online form linked from the town’s procedures page.
• Ozu Town: by post, or online with a smartphone.

Kumamoto City warns that if you report late, the period that can be recalculated is limited by law, so you may have to pay premiums you cannot get back.

Common questions

If I apply late, do I pay less?

No. Kumamoto City charges premiums back to the month you became eligible, for up to two years. Ozu Town charges the tax back for up to three years.

Can I join by post in Kumamoto City?

Yes. Print the application form from the city’s page and send it by post, or hand it in at a ward office or general branch office. Without photo ID at the counter, the document is mailed to you.

Can I apply at a community center in Kumamoto City?

Not for same-day issue. The city says only ward offices and general branch offices can give you the document on the same day.

I am a student who moved to another town for school. Where do I join?

Kumamoto City and Kikuyo Town both describe a special rule: if you moved out to study or to enter a hospital or care facility, you may stay in the National Health Insurance of the city or town you left. Ask the counter there.

Can I join in Kikuyo Town at the Western Branch Office?

The town’s pages name the Health and Insurance Division at the Town Office for joining. The Western Branch Office handles some other National Health Insurance procedures, such as reissuing a lost certificate. Ask before you go.

Sources (checked October 6, 2026)

• Kumamoto City: what National Health Insurance is and who joins, joining and leaving, ward office counter hours
• Kikuyo Town: National Health Insurance, procedures and forms, National Health Insurance tax, Guide to Living in Kikuyo Town, residence card procedures (June 2026), multilingual consultation counter
• Ozu Town: when to notify, tax charged back, tax by month, tax estimate, Foreign Residents Consultation Desk