国民健康保険(こくみんけんこうほけん)資格取得届(しかくしゅとくとどけ)ガイド
EN: Japan requires everyone living in the country for a certain period to have health insurance. If you are not covered by your employer's health insurance (社会保険/健康保険), you generally need to join National Health Insurance (国民健康保険, "Kokuho") through your local municipal office. With it, people under 70 generally pay 30% of medical costs themselves, with Kokuho covering the rest (the percentage is lower for children under 6 and can differ for people 70 and over).
やさしい日本語: 日本(にほん)に一定(いってい)期間(きかん)住(す)む人(ひと)は、健康保険 (けんこうほけん)に入(はい)る必要(ひつよう)があります。会社(かいしゃ)の社会保険(しゃかい ほけん)に入っていない人は、住(す)んでいる市区町村(しくちょうそん)で「国民健康保険(こくみん けんこうほけん、通称(つうしょう)「国保(こくほ)」)」に入ります。国保に入っていると、病院 (びょういん)にかかったとき、自分(じぶん)で払(はら)うお金(かね)が少(すく)なくなります (70歳(さい)未満(みまん)は自己負担(じこふたん)3割(わり)。6歳未満の子(こ)どもや70歳以上 (いじょう)の人(ひと)は割合(わりあい)が違(ちが)います)。
| Situation | Do you need Kokuho? |
|---|---|
| Working for a company that provides 社会保険 (shakai hoken) | Usually NO — you're covered by your employer's insurance instead. Confirm with your employer |
| Working part-time, self-employed, freelance, or a company without 社会保険 | Usually YES — apply for Kokuho at your municipal office |
| Student, or between jobs | Usually YES |
| Dependent family member of someone with 社会保険 | Usually NO — you may be added to their insurance as a dependent (被扶養者) instead. Confirm with their employer |
| Short-term visitor (not a resident) | NO — as a general rule, people whose period of stay is 3 months or less are not eligible (this guide is for medium/long-term residents). A few visa categories (e.g. 興行, 技能実習, 家族滞在, some 特定活動) are excluded even within 3 months, while others with proof of a longer planned stay may still be eligible. |
要確認(自分の在留資格・在留期間がどの区分に当たるかは、勤務先の保険担当者または市区町村の窓口で必ず確認する)
Required to confirm your status and address
Often required or linked automatically after 転入届
If you just left a job that had 社会保険, bring proof that coverage ended, if requested
Bring if you have one; some offices accept a signature instead
The date you became eligible — usually your 転入届 (moving-in) date, or the day after your employer-provided insurance ended. This is NOT the date you visit the counter; even if you apply later, coverage (and premiums) are calculated back to this date.
If living alone, this is you
Calculated based on income, age, and household size, and the rate itself is set by each municipality. Do not guess the amount — ask the counter for your specific calculation. 要確認(金額・料率は自治体・所得により大きく異なるため、必ず窓口で確認)
EN: Apply as soon as you become eligible — typically right after your 転入届 (address registration), or right after your employer-provided insurance ends. Coverage is calculated retroactively to your eligibility start date even if you apply a bit later, which means premiums are also charged retroactively — so applying late does not save money and can create a lump-sum bill.
The exact lookback limit (one municipality states up to 2 years) and whether unpaid medical costs before you filed get reimbursed can differ by municipality. 要確認(遡及の上限期間・届出前の医療費の扱いは自治体により異なるため窓口で確認)
やさしい日本語: 対象(たいしょう)になったらすぐに手続きをしてください。多(おお)くの 場合、転入届と同(おな)じタイミングか、会社の保険が終(お)わった直後(ちょくご)です。手続きが 遅(おそ)れても、保険料は資格を得(え)た日にさかのぼって計算(けいさん)され、 まとめて請求(せいきゅう)されることがあります。早(はや)く手続きしても保険料は変(か)わり ません。
要確認(さかのぼれる期間の上限や、届出前にかかった医療費の扱いは自治体により異なる)
— ask at the counter if you can do both the same day. See the separate 転入届 guide.
Under the National Health Insurance Act (国民健康保険法第5条), anyone with an address in the municipality is required to be enrolled unless they fall under a specific exemption (e.g. already covered by employer insurance, receiving public assistance) — it is not optional. Unpaid medical bills without insurance can be very high.
要確認(自分が適用除外に該当するかどうかの個別判定は窓口で確認)
, which can be confusing for new arrivals with no Japanese income history — ask the counter how your premium is calculated in your first year, as rules for newcomers can differ. 要確認(来日初年度の保険料算定方法は 自治体で確認)
, so your Kokuho start date lines up correctly and you avoid a gap or overlap in coverage.
— it does not automatically stop. Otherwise you may be billed for both.
after applying — ask how long, and what to do if you need to see a doctor before it arrives. 要確認(保険証の発行・郵送期間は自治体により異なる)
*Provided free by Japan Paperwork. Not legal advice. For individual visa/legal questions, consult a licensed 行政書士 (immigration specialist). / 個別の在留資格の相談は行政書士(専門家)へ。*
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