①The insured period of the National Pension before the Effective Date (including the portion relating to a period deemed to be a period during which the person was an insured person of the National Pension pursuant to the provisions of other laws and regulations; the same applies hereinafter in this Article and in Article 32, paragraph (6), Article 78, paragraph (7) and Article 87, paragraph (8) of the Supplementary Provisions) is deemed, for the purpose of applying the National Pension Act, to be an insured period of the National Pension as a category 1 insured person. In this case, of that insured period, the portion relating to a period that was a premium-paid period prescribed in Article 5, paragraph (3) of the former National Pension Act (including a period deemed to be that premium-paid period pursuant to the provisions of other laws and regulations; hereinafter referred to as a "former premium-paid period" in this Article and Article 27 of the Supplementary Provisions) is deemed to be a premium-paid period, the portion relating to a period that was a premium exemption period prescribed in Article 5, paragraph (4) of the former National Pension Act (including a period deemed to be that premium exemption period pursuant to the provisions of other laws and regulations; hereinafter referred to as a "former premium exemption period" in this Article and Article 27 of the Supplementary Provisions) is deemed to be a premium exemption period, and the portion relating to a period that was a former premium-paid period relating to premiums under the provisions of Article 87-2 of the former National Pension Act is deemed to be a premium-paid period relating to premiums under the provisions of Article 87-2 of the National Pension Act.

②Of the periods listed in the following items, the portion relating to the period from April 1, 1961 to the day before the Effective Date (excluding the portion relating to the periods listed in paragraph (5), items (iv)-2 and (vii)-2, and the portion relating to periods before the month that includes the day on which the person reached 20 years of age and periods on and after the month that includes the day on which the person reached 60 years of age) is deemed to be a premium-paid period for the purpose of applying the provisions of Article 26 and Article 37, item (iii) of the National Pension Act and Article 9, paragraph (1), Article 9-2, paragraph (1) and Article 9-2-2, paragraph (1) of the Supplementary Provisions of that Act. In this case, if the same month forms, at the same time, the basis for calculating two or more of the periods listed in the following items or the insured period of the National Pension before the Effective Date, that month is, as specified by Cabinet Order, deemed to be an insured period of the National Pension or a premium-paid period for only one of those periods.

③The periods listed in the items of the preceding paragraph that are deemed to be premium-paid periods of the National Pension pursuant to the provisions of that paragraph (where, in calculating the insured period listed in item (i) of that paragraph, the provisions of Article 47, paragraph (2) or paragraph (3) of the Supplementary Provisions or Article 5, paragraph (2) or paragraph (3) of the Supplementary Provisions of the Act Partially Amending the Employees' Pension Insurance Act, etc. (Act No. 82 of 1996; hereinafter referred to as the "1996 Amendment Act") have been applied, the insured period calculated as if they had not been applied; where, in calculating the period as a member listed in item (ii) of the preceding paragraph, the provisions of Article 32, paragraph (1) of the Supplementary Provisions of the Act Partially Amending the National Public Officers, etc. Mutual Aid Association Act, etc. (Act No. 105 of 1985; hereinafter referred to as the "1985 National Public Officers Mutual Aid Amendment Act") or Article 7, paragraph (2) of the Supplementary Provisions of the 2012 Pension Unification Act have been applied, the period as a member calculated as if they had not been applied; and where, in calculating the period as a member listed in item (iii) of the preceding paragraph, the provisions of Article 35, paragraph (1) of the Supplementary Provisions of the Act Partially Amending the Local Public Officers, etc. Mutual Aid Association Act, etc. (Act No. 108 of 1985; hereinafter referred to as the "1985 Local Public Officers Mutual Aid Amendment Act") or Article 7, paragraph (2) of the Supplementary Provisions of the 2012 Pension Unification Act have been applied, the period as a member calculated as if they had not been applied) are included in the premium-paid period for the purpose of applying the provisions of Article 27 of the National Pension Act.

④For the time being, the premium-paid period of a person who has a premium-paid period relating to the insured period of the National Pension as a category 2 insured person, to the extent that it relates to periods before the month that includes the day on which the person reached 20 years of age and periods on and after the month that includes the day on which the person reached 60 years of age, is, notwithstanding the provisions of Article 5, paragraph (1) of the National Pension Act, not included in the premium-paid period for the purpose of applying the provisions of Articles 26 and 27 of that Act and Article 9, paragraph (1), Article 9-2, paragraph (1) and Article 9-2-2, paragraph (1) of the Supplementary Provisions of that Act, and is included in the credited period for the purpose of applying the provisions of Article 9, paragraph (1) of the Supplementary Provisions of that Act.

⑤The periods listed in the following items are included in the credited period for the purpose of applying the provisions of Article 9, paragraph (1) of the Supplementary Provisions of the National Pension Act:

⑥The calculation of the periods listed in the items of the preceding paragraph (excluding items (iii) through (vi)) is made in the same manner as provided in Article 11 of the new National Pension Act.

⑦Where one or more of the periods listed in the items of paragraph (5) are included in the credited period pursuant to the provisions of that paragraph, the calculation of those periods is as specified by Cabinet Order, taking into consideration the provisions of Article 6 of the former Pension Aggregation General Rules Act.

⑧For the purpose of applying the provisions of Article 18, paragraph (1) of the Supplementary Provisions, Article 26 (including where applied under Article 9-2, paragraph (1) and Article 9-2-2, paragraph (1) of the Supplementary Provisions of that Act) and Article 37, item (iii) of the National Pension Act, and Article 9, paragraph (1) of the Supplementary Provisions of that Act, when calculating the insured period of the National Pension as a category 2 insured person for a period during which a person was an insured person of the National Pension who was a class 3 insured person, etc. (meaning a class 3 insured person or a voluntarily continued mariner insured person; the same applies hereinafter in this paragraph and in Article 47, paragraph (4), Article 52 and Article 82, paragraph (1) of the Supplementary Provisions) or a new mariner member (meaning a new mariner member prescribed in Article 32, paragraph (2) of the Supplementary Provisions of the 1985 National Public Officers Mutual Aid Amendment Act and a new mariner member prescribed in Article 35, paragraph (2) of the Supplementary Provisions of the 1985 Local Public Officers Mutual Aid Amendment Act; the same applies hereinafter in this paragraph) before April 1, 1991, or for a period during which a person was a new mariner member prescribed in Article 5, paragraph (3) of the Supplementary Provisions of the 1996 Amendment Act (hereinafter referred to in this paragraph as a "former applicable-corporation mariner member") that is deemed, pursuant to the provisions of paragraph (1) of that Article, to be a period during which the person was an insured person of Employees' Pension Insurance, the period obtained by multiplying the period calculated pursuant to the provisions of Article 11, paragraphs (1) and (2) and Article 11-2 of the new National Pension Act by six-fifths is, notwithstanding those provisions, to be the insured period of the National Pension as a category 2 insured person. In this case, a month in which there was a change in the classification of whether or not the person was a class 3 insured person, etc., a new mariner member or a former applicable-corporation mariner member is deemed to be a month during which the person was an insured person of the National Pension in the classification after the change (or, where there were two or more changes in the classification of whether or not the person was a class 3 insured person, etc., a new mariner member or a former applicable-corporation mariner member in the same month, the last classification).

⑨The periods listed in the items of paragraph (2) as prescribed in paragraph (3) and the periods listed in paragraph (5), items (iii) through (vi) are deemed to be insured periods of the National Pension that are premium-paid periods, for the purpose of applying the provisions of the proviso to Article 30, paragraph (1) of the National Pension Act (including as applied mutatis mutandis pursuant to Article 30-2, paragraph (2), Article 30-3, paragraph (2), Article 34, paragraph (5) and Article 36, paragraph (3) of that Act) and the proviso to Article 37 of that Act. In this case, if the same month forms, at the same time, the basis of two or more of the periods listed in the items of paragraph (2) as prescribed in paragraph (3) or the periods listed in paragraph (5), items (iii) through (vi), that month is, as specified by Cabinet Order, deemed to be an insured period of the National Pension that is a premium-paid period for only one of those periods.

⑩The calculation of the periods listed in paragraph (5), items (iii) through (vi) where those periods are deemed to be insured periods of the National Pension that are premium-paid periods pursuant to the provisions of the preceding paragraph is as specified by Cabinet Order, taking into consideration the method of calculating the periods listed in the items of paragraph (2) where those periods are included in the premium-paid period pursuant to the provisions of paragraph (3).

⑪When the right to collect premiums of Employees' Pension Insurance or Mariners Insurance for the category 1 employees' pension insured period under paragraph (2), item (i) has been extinguished by prescription (excluding when the case falls under the proviso to Article 75 of the new Employees' Pension Insurance Act, when it falls under the proviso to Article 75, paragraph (1) of the former Employees' Pension Insurance Act and when it falls under the proviso to Article 51-2 of the former Mariners Insurance Act), the provisions of paragraph (2) do not apply to that category 1 employees' pension insured period relating to those premiums, and that category 1 employees' pension insured period is, notwithstanding the provisions of paragraph (5), not included in the credited period for the purpose of applying the provisions of Article 9, paragraph (1) of the Supplementary Provisions of the National Pension Act, and is, notwithstanding the provisions of paragraph (9), deemed to be an insured period of the National Pension other than a premium-paid period (including a former premium-paid period) and a premium exemption period (including a former premium exemption period) for the purpose of applying the provisions of that Act prescribed in that paragraph.

⑫With regard to a notification under Article 7-3 of the Supplementary Provisions of the new National Pension Act that is made on or before April 30, 1991, the phrase "the second month before the month" in that Article is deemed to be replaced with "the month before the most recent reference month (meaning January, April, July and October) preceding the month".