With respect to the portion of the old-age basic pension under the National Pension Act (hereinafter referred to simply as the "old-age basic pension" in this Article) for the months from the month containing the day following the date specified by Cabinet Order under Article 98 of the Supplementary Provisions until the month containing the day on which one year has elapsed from that following day, payable to a person entitled to receive the old-age basic pension (excluding a specific recipient prescribed in Article 9-4-4 of the Supplementary Provisions of the National Pension Act after the amendment), that is equivalent to the amount obtained by deducting, from the amount payable in each payment month based on the right to receive the old-age basic pension revised under the provisions of the main clause of Article 9-4-3, paragraph (4) of the Supplementary Provisions of the National Pension Act after the amendment, the amount that would have been payable in each payment month had that revision not been made, such portion is, notwithstanding the provisions of the main clause of Article 18, paragraph (3) of the National Pension Act after the amendment, to be paid in the month two months after the month containing that day on which the period has elapsed.