# 厚生年金保険法 / Employees' Pension Insurance Act — 第二十三条 (Supplementary Provisions, Article 23)

- Law: 厚生年金保険法 (Employees' Pension Insurance Act), 昭和二十九年法律第百十五号
- English title "Employees' Pension Insurance Act": Ministry of Justice translation
- Kind: Act — the distinction between 法律 (Act), 政令 (Cabinet Order), 省令 (Ministerial Order) and 条例 (local ordinance) decides who may issue it and what it may say.
- Provision: 第二十三条 (Supplementary Provisions, Article 23) — address `suppl-5071-74/art-23`
- Text in force since: 2026-10-01
- URL (the page that opens at this provision): https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23
- Permanent URL (e-Gov law ID, never renamed): https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23
- Every provision below carries its address and both URLs on the line under it.
- Japanese text: e-Gov 法令検索, Digital Agency (デジタル庁). English: as marked on each line below.

Only the Japanese as published by the government has legal effect; the text
below is a copy of it. Every English rendering below is a translation and
says which kind: the Ministry of Justice's translation, or this
site's machine translation, whose model and date the Sources list names.
They are never merged and never substituted for one another.

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### 第二十三条
<sup>suppl-5071-74/art-23 · https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23</sup>

**第一項**  令和十七年十月一日以後に第十四号改正後厚年法第六条第三項の規定により適用事業所となった事業所又は事務所の事業主その他政令で定める事業所又は事務所の事業主（既にこの項の申出をした事業主を除く。以下この項において同じ。）は、当該適用事業所となった日（当該政令で定める事業所又は事務所の事業主にあっては、政令で定める日）から起算して二年を経過した日が属する月の前月までの間に、主務省令で定めるところにより実施機関に申出をした場合は、厚生年金保険法第八十二条第一項及び前条の規定にかかわらず、当分の間、適用事業所に使用される短時間被保険者に係る事業主の負担すべき厚生年金保険料（同法第二十四条の四第一項の規定により決定された標準賞与額に係るもの及び同法第八十六条第一項の規定により指定された期限までに納付されていないものを除く。以下この項において「短時間被保険者に係る厚生年金保険料」という。）の負担の割合を、増加負担割合に百分の五十を加えた割合に増加することができる。この場合において、短時間被保険者に係る厚生年金保険料の額のうち、短時間被保険者に係る標準報酬月額に同法第八十一条第四項に規定する保険料率を乗じて得た額に相当する額に増加負担割合を乗じて得た額は、徴収を行うことを要しなかったものとみなす。
<sup>suppl-5071-74/art-23/par-1 · https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-1</sup>
The employer of a place of business or office that became an applicable place of business pursuant to the provisions of Article 6, paragraph (3) of the Employees' Pension Insurance Act as Amended by the item (xiv) Provisions on or after October 1, 2035, or the employer of any other place of business or office specified by Cabinet Order (excluding an employer that has already made the application under this paragraph; the same applies hereinafter in this paragraph) may, if the employer applies to an implementing organization, as provided by order of the competent ministry, during the period up to the month preceding the month that includes the day on which two years have elapsed from the day on which it became that applicable place of business (for the employer of a place of business or office specified by Cabinet Order, the date specified by Cabinet Order), increase, for the time being, notwithstanding Article 82, paragraph (1) of the Employees' Pension Insurance Act and the preceding Article, the ratio of the burden to be borne by the employer for the employees' pension insurance premiums pertaining to part-time insureds employed at the applicable place of business (excluding those pertaining to the standard bonus amount decided under Article 24-4, paragraph (1) of that Act and those not paid by the due date designated under Article 86, paragraph (1) of that Act; hereinafter in this paragraph referred to as "employees' pension insurance premiums for part-time insureds") to the ratio obtained by adding 50/100 to the increased burden ratio. In this case, of the amount of employees' pension insurance premiums for part-time insureds, the amount obtained by multiplying the increased burden ratio by the amount equivalent to the amount obtained by multiplying the standard monthly remuneration for part-time insureds by the insurance premium rate prescribed in Article 81, paragraph (4) of the Employees' Pension Insurance Act is deemed not to have required collection.
<sup>machine translation, not official</sup>

**第二項**  前条第三項から第十一項までの規定は、前項の規定を適用する場合について準用する。この場合において、これらの規定の適用に関し必要な読替えその他必要な事項は、政令で定める。
<sup>suppl-5071-74/art-23/par-2 · https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-2 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-2</sup>
The provisions of paragraphs (3) through (11) of the preceding Article apply mutatis mutandis to the case where the provisions of the preceding paragraph are applied. In this case, the necessary replacement of terms for the application of these provisions and other necessary matters are specified by Cabinet Order.
<sup>machine translation, not official</sup>

**第三項**  この条において「短時間被保険者」とは、次の各号のいずれかに該当する者であって、第九号改正後厚年法第十二条各号のいずれにも該当しないもの（平成二十四年機能強化法附則第十六条の規定により第九号改正後厚年法第十二条（第五号に係る部分に限る。）の規定が適用されない者を除く。）であり、かつ、七十歳未満である厚生年金保険の被保険者（標準報酬月額等級のうち第一級から第六級までに該当する者に限る。）であるものをいう。
<sup>suppl-5071-74/art-23/par-3 · https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-3 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-3</sup>
In this Article, "part-time insured" means an insured covered by employees' pension insurance who falls under any of the following items and does not fall under any of the items of Article 12 of the Employees' Pension Insurance Act as Amended by the item (ix) Provisions (excluding a person for whom the provisions of Article 12 (limited to the part pertaining to item (v)) of the Employees' Pension Insurance Act as Amended by the item (ix) Provisions are not applied under the provisions of Article 16 of the Supplementary Provisions of the 2012 Pension Function Strengthening Act), and who is under 70 years of age (limited to those who fall under grade 1 through grade 6 of the standard monthly remuneration grades).
<sup>machine translation, not official</sup>

  **一**  一週間の所定労働時間が同一の事業所又は事務所に使用される通常の労働者（第九号改正後厚年法第十二条第五号に規定する通常の労働者をいう。次号において同じ。）の一週間の所定労働時間の四分の三未満である短時間労働者（同条第五号に規定する短時間労働者をいう。次号において同じ。）
  <sup>suppl-5071-74/art-23/par-3/item-1 · https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-3/item-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-3/item-1</sup>
  a part-time worker (meaning a part-time worker prescribed in Article 12, item (v) of the Employees' Pension Insurance Act as Amended by the item (ix) Provisions; the same applies in the following item) whose scheduled working hours per week are less than three-quarters of the scheduled working hours per week of an ordinary worker (meaning an ordinary worker prescribed in that item; the same applies in the following item) employed at the same place of business or office;
  <sup>machine translation, not official</sup>

  **二**  一月間の所定労働日数が同一の事業所又は事務所に使用される通常の労働者の一月間の所定労働日数の四分の三未満である短時間労働者
  <sup>suppl-5071-74/art-23/par-3/item-2 · https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-3/item-2 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-3/item-2</sup>
  a part-time worker whose prescribed working days per month are less than three-quarters of the prescribed working days per month of an ordinary worker employed at the same place of business or office.
  <sup>machine translation, not official</sup>

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## Cites
- suppl-5071-74/art-23/par-1: この項 → 厚生年金保険法 附則第二十三条第一項 (Supplementary Provisions, Article 23, paragraph (1)), suppl-5071-74/art-23/par-1 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-1
- suppl-5071-74/art-23/par-1: 厚生年金保険法第八十二条第一項 → 厚生年金保険法 第八十二条第一項 (Article 82, paragraph (1)), art-82/par-1 — https://japanlaw.org/ja/employees-pension-insurance-act/art-82/par-1 · https://japanlaw.org/l/329AC0000000115/art-82/par-1
- suppl-5071-74/art-23/par-1: 前条 → 厚生年金保険法 附則第二十二条 (Supplementary Provisions, Article 22), suppl-5071-74/art-22 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22
- suppl-5071-74/art-23/par-1: 同法第二十四条の四第一項 → 厚生年金保険法 第二十四条の四第一項 (Article 24-4, paragraph (1)), art-24-4/par-1 — https://japanlaw.org/ja/employees-pension-insurance-act/art-24-4/par-1 · https://japanlaw.org/l/329AC0000000115/art-24-4/par-1
- suppl-5071-74/art-23/par-1: 同法第八十六条第一項 → 厚生年金保険法 第八十六条第一項 (Article 86, paragraph (1)), art-86/par-1 — https://japanlaw.org/ja/employees-pension-insurance-act/art-86/par-1 · https://japanlaw.org/l/329AC0000000115/art-86/par-1
- suppl-5071-74/art-23/par-1: 同法第八十一条第四項 → 厚生年金保険法 第八十一条第四項 (Article 81, paragraph (4)), art-81/par-4 — https://japanlaw.org/ja/employees-pension-insurance-act/art-81/par-4 · https://japanlaw.org/l/329AC0000000115/art-81/par-4
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第十項 (Supplementary Provisions, Article 22, paragraph (10)), suppl-5071-74/art-22/par-10 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-10 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-10
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第十一項 (Supplementary Provisions, Article 22, paragraph (11)), suppl-5071-74/art-22/par-11 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-11 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-11
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第三項 (Supplementary Provisions, Article 22, paragraph (3)), suppl-5071-74/art-22/par-3 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-3 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-3
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第四項 (Supplementary Provisions, Article 22, paragraph (4)), suppl-5071-74/art-22/par-4 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-4 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-4
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第五項 (Supplementary Provisions, Article 22, paragraph (5)), suppl-5071-74/art-22/par-5 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-5 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-5
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第六項 (Supplementary Provisions, Article 22, paragraph (6)), suppl-5071-74/art-22/par-6 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-6 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-6
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第七項 (Supplementary Provisions, Article 22, paragraph (7)), suppl-5071-74/art-22/par-7 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-7 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-7
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第八項 (Supplementary Provisions, Article 22, paragraph (8)), suppl-5071-74/art-22/par-8 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-8 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-8
- suppl-5071-74/art-23/par-2: 前条第三項から第十一項まで → 厚生年金保険法 附則第二十二条第九項 (Supplementary Provisions, Article 22, paragraph (9)), suppl-5071-74/art-22/par-9 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-9 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-9
- suppl-5071-74/art-23/par-2: 前項 → 厚生年金保険法 附則第二十三条第一項 (Supplementary Provisions, Article 23, paragraph (1)), suppl-5071-74/art-23/par-1 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-1
- suppl-5071-74/art-23/par-3: この条 → 厚生年金保険法 附則第二十三条 (Supplementary Provisions, Article 23), suppl-5071-74/art-23 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23
- suppl-5071-74/art-23/par-3: 第九号改正後厚年法第十二条 → 厚生年金保険法 第十二条 (Article 12), art-12 — https://japanlaw.org/ja/employees-pension-insurance-act/art-12 · https://japanlaw.org/l/329AC0000000115/art-12
- suppl-5071-74/art-23/par-3: 第五号 → 厚生年金保険法 第十二条第一項第五号 (Article 12, paragraph (1), item (v)), art-12/par-1/item-5 — https://japanlaw.org/ja/employees-pension-insurance-act/art-12/par-1/item-5 · https://japanlaw.org/l/329AC0000000115/art-12/par-1/item-5
- suppl-5071-74/art-23/par-3/item-1: 第九号改正後厚年法第十二条第五号 → 厚生年金保険法 第十二条第一項第五号 (Article 12, paragraph (1), item (v)), art-12/par-1/item-5 — https://japanlaw.org/ja/employees-pension-insurance-act/art-12/par-1/item-5 · https://japanlaw.org/l/329AC0000000115/art-12/par-1/item-5
- suppl-5071-74/art-23/par-3/item-1: 次号 → 厚生年金保険法 附則第二十三条第三項第二号 (Supplementary Provisions, Article 23, paragraph (3), item (ii)), suppl-5071-74/art-23/par-3/item-2 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-3/item-2 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-3/item-2

## Cited by

8 provisions cite this one. No official source publishes this direction.

- 厚生年金保険法 附則第十七条第一項（厚生年金保険の短時間労働者への適用に関する経過措置） — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-17/par-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-17/par-1
- 厚生年金保険法 附則第二十二条第一項（短時間被保険者に係る厚生年金保険料に関する経過措置） — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-1
- 厚生年金保険法 附則第二十二条第八項（短時間被保険者に係る厚生年金保険料に関する経過措置） — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-22/par-8 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-22/par-8
- 厚生年金保険法 附則第二十三条第一項 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-1
- 厚生年金保険法 附則第二十三条第二項 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-2 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-2
- 厚生年金保険法 附則第二十三条第三項 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-3 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-3
- 厚生年金保険法 附則第二十三条第三項第一号 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/art-23/par-3/item-1 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/art-23/par-3/item-1
- 厚生年金保険法 附則別表第二 — https://japanlaw.org/ja/employees-pension-insurance-act/suppl-5071-74/appdx-2 · https://japanlaw.org/l/329AC0000000115/suppl-5071-74/appdx-2

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## Sources

- e-Gov 法令検索, Digital Agency (デジタル庁) — 厚生年金保険法 — the text in force from 2026-10-01 (https://laws.e-gov.go.jp/law/329AC0000000115/20261001_507AC0000000074), retrieved 2026-10-13
- Japanese Law Translation Database System, Ministry of Justice (法務省) — Employees' Pension Insurance Act — Ministry of Justice translation (https://www.japaneselawtranslation.go.jp/en/laws/view/3554/tb), retrieved 2026-10-13
- claude-sonnet-5-5 — Machine translation, batch employees-pension-insurance-act-20261013T074650-102, translated 2026-10-13
- claude-sonnet-5-5 — Machine translation, batch employees-pension-insurance-act-20261013T083844-007, translated 2026-10-19
- This site's parser, version 211 — 厚生年金保険法 — structure, counts, cross-references and defined terms, computed 2026-10-13