This Act comes into effect on April 1, 2026; provided, however, that the provisions set forth in the following items come into effect on the dates specified respectively in those items:

①The government is to, promptly after this Act comes into effect, taking into consideration the conditions of enforcement, etc. of each Act as amended by this Act, from the viewpoint of further advancing efforts to make the public pension system sustainable over the long term, further strengthening its security function in response to changes in the socioeconomic situation, and ensuring fairness between and within generations, continue to examine the matters set forth in the items of Article 6, paragraph (2) of the Act on the Promotion of Reform to Establish a Sustainable Social Security System (Act No. 112 of 2013) and the strengthening of the income redistribution function of the public pension system and other necessary matters (excluding the matters specified in the following paragraph through paragraph (4)), with respect to the public pension system and systems related to it, and is to take necessary measures based on the results thereof.

②The government is to, in light of the state of enforcement of each Act as amended by this Act, the current state and outlook of finances prescribed in Article 4-3, paragraph (1) of the National Pension Act and the current state and outlook of finances prescribed in Article 2-4, paragraph (1) of the Employees' Pension Insurance Act, which are prepared for the first time on or after the date of promulgation of this Act, and other matters, while paying attention to the ideal form, etc. of the National Health Insurance system, continue to examine the scope of application of Employees' Pension Insurance and health insurance, and is to take necessary measures based on the results thereof.

①If the employer (excluding an employer that has already made the application under this paragraph; the same applies hereinafter in this Article) of an applicable place of business for health insurance set forth in each of the following items (excluding an applicable place of business of the State or a local government; hereinafter simply referred to as an "applicable place of business" in this paragraph and paragraph (1) of the following Article) makes an application to the insurer, etc. (meaning, for health insurance administered by the Japan Health Insurance Association, the Minister of Health, Labour and Welfare, and for health insurance administered by a health insurance society, that health insurance society; the same applies hereinafter in this Article and paragraph (1) of the following Article) as specified by Order of the Ministry of Health, Labour and Welfare, by the month preceding the month which contains the day on which two years have elapsed from the date specified in each such item (referred to as the "base date" in paragraphs (4) and (5)), the employer may, for the time being, notwithstanding Article 161, paragraph (1) of the Health Insurance Act, increase the proportion of the insurance premiums prescribed in Article 155, paragraph (1) of that Act that the employer is to bear for part-time insured persons employed at the applicable place of business (excluding those appropriated to the costs required for health insurance services prescribed in that paragraph (limited to the costs required for payment of the levies under the provisions of the Long-Term Care Insurance Act (Act No. 123 of 1997), the children and child-rearing support levy under the provisions of the Act on Support for Children and Child-rearing (Act No. 65 of 2012) and, in the case of part-time insured persons administered by a health insurance society, the contributions under the provisions of Article 173 of the Health Insurance Act), those pertaining to the standard bonus amount determined pursuant to Article 45, paragraph (1) of that Act, and those not paid by the time limit designated pursuant to Article 180, paragraph (1) of that Act; hereinafter in this paragraph and paragraph (7) referred to as the "health insurance premium for part-time insured persons") to the proportion obtained by adding 50% to the proportion specified in each item of Appended Table 3 of the Supplementary Provisions according to the category of period set forth in that item (hereinafter in this Article, paragraph (1) of the following Article and Appended Table 3 of the Supplementary Provisions referred to as the "increased burden ratio"). In this case, the amount (referred to as the "premium adjustment amount" in paragraphs (4) and (10)) obtained by multiplying the amount equivalent to the amount obtained by multiplying the standard monthly remuneration amount for part-time insured persons by the general insurance premium rate prescribed in Article 160, paragraph (1) of that Act, within the amount of the health insurance premium for part-time insured persons, by the increased burden ratio (where a health insurance society has increased the proportion of the general insurance premium amount to be borne by the employer pursuant to Article 162 of that Act, the proportion obtained by deducting from the increased burden ratio the proportion increased pursuant to that Article (or zero if that proportion falls below zero)) is deemed not to have been required to be collected.

③The application under paragraph (1) must, in the case of an employer that is able to make the application under Article 22, paragraph (1) of the Supplementary Provisions, be made at the same time as the application under that paragraph.

④Where the premium adjustment amount for each applicable place of business prescribed in paragraph (1) is zero (excluding the case where the month in which the premium adjustment amount is zero falls within a period on or after the month which contains the day on which two years have elapsed from the base date), the application of the provisions of that paragraph to that applicable place of business is to be suspended for the period on or after the month in which the premium adjustment amount is zero.

⑤An employer may, between the month in which the application of the provisions of paragraph (1) was suspended pursuant to the provisions of the preceding paragraph and the month preceding the month which contains the day on which two years have elapsed from the base date, apply to the insurer, etc., as specified by Order of the Ministry of Health, Labour and Welfare, for release of the suspension under the preceding paragraph.

⑥The application for release under the preceding paragraph must, in the case of an employer that is able to apply for release under paragraph (5) of Article 22 of the Supplementary Provisions pursuant to the provisions of that paragraph, be made at the same time as the application for release under that paragraph.

⑦The provisions of paragraph (1) apply to the health insurance premium for part-time insured persons for each of the 36 months counted cumulatively from the month which contains the day on which the application under that paragraph was made; provided, however, that each month from the month in which the application of the provisions of paragraph (1) was suspended pursuant to the provisions of paragraph (4) up to the month preceding the month which contains the day on which the application for release under paragraph (5) was made is not to be counted cumulatively.

⑧The government may, taking into account trends in the minimum wage, etc., by Cabinet Order, revise the grading of the standard monthly remuneration amount by adding a further grade above the highest grade of the standard monthly remuneration grades prescribed in Article 40, paragraph (1) of the Health Insurance Act set forth in the upper column of the table in each item of Appended Table 3 of the Supplementary Provisions (referred to simply as "standard monthly remuneration grades" in paragraph (11), paragraph (3) of the following Article and Appended Table 3 of the Supplementary Provisions), and revise the increased burden ratio specified in the lower column of that table (with 25% as the upper limit). In this case, the phrase "through grade 9" in paragraph (11) is deemed to be replaced with "through the grade specified by Cabinet Order", and beyond that, other matters necessary for the application of the provisions of this paragraph are specified by Cabinet Order.

⑨The affairs pertaining to the authority to accept applications by the insurer, etc. (limited to the Minister of Health, Labour and Welfare) under paragraphs (1) and (5) are to be performed by the Japan Pension Service. In this case, the phrase ", the Mariners Insurance Act" in Article 23, paragraph (3) of the Japan Pension Organization Act is deemed to be replaced with ", or the Act Partially Amending the National Pension Act, etc., and Other Matters, to Strengthen the Functions of the Pension System in Light of Socioeconomic Changes (Act No. 74 of 2025), the Mariners Insurance Act", the phrase "the Health Insurance Act" in Article 26, paragraph (2) of that Act is deemed to be replaced with "the Health Insurance Act or the Act Partially Amending the National Pension Act, etc., and Other Matters, to Strengthen the Functions of the Pension System in Light of Socioeconomic Changes", the phrase "affairs pertaining to the authority prescribed in it, and that Act" in Article 27, paragraph (2), item (ii) of that Act is deemed to be replaced with "and affairs pertaining to the authority prescribed in Article 24, paragraph (9) of the Supplementary Provisions of the Act Partially Amending the National Pension Act, etc., and Other Matters, to Strengthen the Functions of the Pension System in Light of Socioeconomic Changes, and the Health Insurance Act", "及び" (and) is deemed to be replaced with "並びに" (and, joining larger groups of items), and the phrase "the Health Insurance Act" in Article 48, paragraph (1) of that Act is deemed to be replaced with "the Health Insurance Act or the Act Partially Amending the National Pension Act, etc., and Other Matters, to Strengthen the Functions of the Pension System in Light of Socioeconomic Changes".

⑩Beyond what is provided for in the preceding paragraphs, a refund of an amount equivalent to the premium adjustment amount deemed under the provisions of paragraph (1) not to have been required to be collected, and other necessary matters, are specified by Cabinet Order.

⑪In this Article, a "part-time insured person" means a person who is a specified under-three-quarters part-time worker prescribed in Article 46, paragraph (1) of the Supplementary Provisions of the 2012 Pension Function Strengthening Act and who is an insured person of health insurance (limited to a person who falls under grade 1 through grade 9 of the standard monthly remuneration grades).

①If the employer of a place of business that became an applicable place of business pursuant to Article 31, paragraph (1) of the Health Insurance Act on or after October 1, 2035, or the employer of another place of business specified by Cabinet Order (excluding an employer that has already made the application under this paragraph; the same applies hereinafter in this paragraph), makes an application to the insurer, etc. as specified by Order of the Ministry of Health, Labour and Welfare, by the month preceding the month which contains the day on which two years have elapsed from the day on which the place of business became that applicable place of business (for the employer of a place of business specified by Cabinet Order, the day specified by Cabinet Order), the employer may, for the time being, notwithstanding Article 161, paragraph (1) of that Act and the preceding Article, increase the proportion of the insurance premiums prescribed in Article 155, paragraph (1) of that Act that the employer is to bear for part-time insured persons employed at the applicable place of business (excluding those appropriated to the costs required for health insurance services prescribed in that paragraph (limited to the costs required for payment of the levies under the provisions of the Long-Term Care Insurance Act, the children and child-rearing support levy under the provisions of the Act on Support for Children and Child-rearing and, in the case of part-time insured persons administered by a health insurance society, the contributions under the provisions of Article 173 of the Health Insurance Act), those pertaining to the standard bonus amount determined pursuant to Article 45, paragraph (1) of that Act, and those not paid by the time limit designated pursuant to Article 180, paragraph (1) of that Act; hereinafter in this paragraph referred to as the "health insurance premium for part-time insured persons") to the proportion obtained by adding 50% to the increased burden ratio. In this case, the amount obtained by multiplying the amount equivalent to the amount obtained by multiplying the standard monthly remuneration amount for part-time insured persons by the general insurance premium rate prescribed in Article 160, paragraph (1) of that Act, within the amount of the health insurance premium for part-time insured persons, by the increased burden ratio (where a health insurance society has increased the proportion of the general insurance premium amount to be borne by the employer pursuant to Article 162 of that Act, the proportion obtained by deducting from the increased burden ratio the proportion increased pursuant to that Article (or zero if that proportion falls below zero)) is deemed not to have been required to be collected.

②The provisions of paragraphs (3) through (10) of the preceding Article apply mutatis mutandis to the case of applying the provisions of the preceding paragraph. In this case, necessary replacement of terms in applying those provisions and other necessary matters are specified by Cabinet Order.

③In this Article, a "part-time insured person" means a person who falls under any of the following items, who does not fall under any of the items of Article 3, paragraph (1) of the Health Insurance Act as amended by the provisions of Article 33 (limited to the amending provision set forth in Article 1, paragraph (1), item (ix) of the Supplementary Provisions) (hereinafter in this paragraph and Article 38 of the Supplementary Provisions referred to as the "item (ix) Amended Health Insurance Act") (excluding a person to whom the provisions of Article 3, paragraph (1) of the item (ix) Amended Health Insurance Act (limited to the part pertaining to item (ix)) are not applied pursuant to Article 45 of the Supplementary Provisions of the 2012 Pension Function Strengthening Act), and who is an insured person of health insurance (limited to a person who falls under grade 1 through grade 9 of the standard monthly remuneration grades).

For a person to whom the provisions of Article 3, paragraph (1) of the item (ix) Amended Health Insurance Act (limited to the part pertaining to item (ix)) are not applied pursuant to Article 45 of the Supplementary Provisions of the 2012 Pension Function Strengthening Act, and who continues to hold the qualification of an insured person of health insurance until the item (ix) effective date, the provisions of Article 8-3-2 of the Supplementary Provisions of the item (ix) Amended Health Insurance Act do not apply while the person, on or after the item (ix) effective date, continues to be employed at the place of business at which the person was employed on the item (v) effective date of the Pension Function Strengthening Act.

With respect to the application of penal provisions to an act committed before this Act (with respect to the provisions set forth in item (xv) of Article 1, paragraph (1) of the Supplementary Provisions, before those provisions) comes into effect, and to an act committed on or after the effective date of item (xv) in a case where those provisions are to remain in force under Article 36, paragraph (1) of the Supplementary Provisions, the provisions then in force continue to govern.

Beyond what is provided for in these Supplementary Provisions, transitional measures necessary in connection with the enforcement of this Act (including transitional measures concerning penal provisions) are specified by Cabinet Order.