Supplementary Provisions, Article 4
第四条
The amount of insurance premiums that a class 4 insured person under employees' pension insurance who, before November 1, 1973, prepaid insurance premiums for a period on or after that day is to additionally pay for each month of the period covered by the prepayment is, for each month of that period, the amount obtained by deducting, from the amount of insurance premiums that would be payable under the provisions of the Employees' Pension Insurance Act as amended by this Act if the person had not made the prepayment, the amount of insurance premiums that would be payable if the provisions of that Act prior to its amendment by this Act were applied.
昭和四十八年十一月一日前に同日以後の期間に係る保険料を前納した厚生年金保険の第四種被保険者が当該前納に係る期間の各月につき追加して納付すべき保険料の額は、当該期間の各月につき、その者が前納しなかつたとしたならば、この法律による改正後の厚生年金保険法の規定により納付すべきこととなる保険料の額からこの法律による改正前の同法の規定を適用したとした場合において納付すべきこととなる保険料の額を控除した額とする。
In the case where the amount of an employees' old-age pension under the Employees' Pension Insurance Act is calculated for a person who has the period prescribed in the preceding paragraph, if there is a month for which insurance premiums were not paid in the amount prescribed in that paragraph, the amount specified in Article 43 of that Act (including as applied pursuant to Article 44, paragraph (1) of that Act) or Article 9, paragraph (1) of the Supplementary Provisions of that Act is, notwithstanding those provisions, the amount obtained by deducting from the amount prescribed in those provisions the amount obtained by multiplying 540 yen by the number of months of the insured period under employees' pension insurance for the month for which the insurance premiums were not paid.
前項の期間を有する者について、厚生年金保険法による老齢厚生年金の額を計算する場合において、同項に規定する額による保険料の納付が行われなかつた月があるときは、同法第四十三条（同法第四十四条第一項において適用する場合を含む。）又は同法附則第九条第一項に定める額は、これらの規定にかかわらず、これらの規定に規定する額から五百四十円に当該保険料の納付が行われなかつた月に係る厚生年金保険の被保険者期間の月数を乗じて得た額を控除した額とする。
The provisions of the preceding paragraph apply mutatis mutandis to a person who has the period prescribed in Article 9, paragraph (1) of the Supplementary Provisions prior to their amendment by the provisions of Article 6 of the Act Partially Amending the National Pension Act, etc. (Act No. 34 of 1985; hereinafter referred to as the "1985 Amendment Act") (hereinafter in this paragraph referred to as the "supplementary provisions before the amendment"), in the case where, when the amount of an employees' old-age pension is calculated on the basis of the portion of that period that is deemed, pursuant to the provisions of Article 47, paragraph (1) of the Supplementary Provisions of the 1985 Amendment Act, to be a period of having been an insured covered by employees' pension insurance, there is a month for which insurance premiums were not paid in the amount prescribed in Article 9, paragraph (1) of the supplementary provisions before the amendment.
前項の規定は、国民年金法等の一部を改正する法律（昭和六十年法律第三十四号。以下「昭和六十年改正法」という。）第六条の規定による改正前の附則（以下この項において「改正前の附則」という。）第九条第一項の期間を有する者について、当該期間のうち同法附則第四十七条第一項の規定により厚生年金保険の被保険者であつた期間とみなされた期間に基づいて老齢厚生年金の額を計算する場合において、改正前の附則第九条第一項に規定する額による保険料の納付が行われなかつた月があるときに準用する。