Canada Pension Plan — C-8 59.1
Amount of post-retirement benefit 59.1 (1) A post-retirement benefit payable to a contributor is a basic monthly amount that is equal to the aggregate of the amounts calculated as provided in subsections (1.1), (3) and (5). Calculation of portion of post-retirement benefit (1.1) Subject to subsections (2) and (7), the amount that is to be used for the purpose of subsection (1) is determined by the formula [(A × F/B) × C × D × E]/12 where A is the amount determined under subsection 53(1) for the year before the year in which the post-retirement benefit commences to be payable; B is the Year’s Maximum Pensionable Earnings for the year before the year in which the post-retirement benefit commences to be payable; C is 0.00625; D is the Maximum Pensionable Earnings Average for the year in which the post-retirement benefit commences to be payable; E is the adjustment factor referred to in subsection 46(3) or (3.1), as the case may be, based on the age of the contributor on January 1 of the year in which the post-retirement benefit commences to be payable; and F is the amount determined by the formula G/H where G is the amount of the earnings referred to in subparagraph 53(1)(b)(i), and H is the aggregate of the earnings referred to in subparagraph 53(1)(b)(i) and those referred to in subparagraph 53(1)(b)(ii). Base unadjusted pensionable earnings for year retirement pension becomes payable (2) For the purpose of the calculation under subsection (1.1), if the contributor’s base unadjusted pensionable earnings are earned in the year in which the contributory period ends under subparagraph 49(b)(iii), the amount determined for A in that subsection is the greater of (a) zero, and (b) the amount that is calculated by subtracting the Year’s Maximum Pensionable Earnings for that year — multiplied by the number of months in the year before the retirement pension becomes payable and divided by 12 — from the amount determined under subsection 53(1). Calculation of portion of post-retirement benefit (3) Subject to subsections (4) and (7), the amount that is to be used for the purpose of subsection (1) is determined by the formula [(A × F/B) × C × D × E]/12 where A is the amount determined under subsection 53.1(1) for the year before the year in which the post-retirement benefit commences to be payable, except that (a) if the post-retirement benefit commences in 2020, A is the amount for 2019, multiplied by 0.15, (b) if the post-retirement benefit commences in 2021, A is the amount for 2020, multiplied by 0.3, (c) if the post-retirement benefit commences in 2022, A is the amount for 2021, multiplied by 0.5, and (d) if the post-retirement benefit commences in 2023, A is the amount for 2022, multiplied by 0.75; B is the Year’s Maximum Pensionable Earnings for the year before the year in which the post-retirement benefit commences to be payable; C is 0.00208; D is the Maximum Pensionable Earnings Average for the year in which the post-retirement benefit commences to be payable; E is the adjustment factor referred to in subsection 46(3.1), based on the age of the contributor on January 1 of the year in which the post-retirement benefit commences to be payable; and F is the amount determined by the formula G/H where G is the amount of the earnings referred to in subparagraph 53.1(1)(b)(i), and H is the aggregate of the earnings referred to in subparagraph 53.1(1)(b)(i) and those referred to in subparagraph 53.1(1)(b)(ii). First additional unadjusted pensionable earnings for year retirement pension becomes payable (4) For the purpose of the calculation under subsection (3), if the contributor’s first additional unadjusted pensionable earnings are earned in the year in which the first additional contributory period ends under paragraph 49.1(c), the amount determined for A in that subsection is the greater of (a) zero, and (b) the amount that is calculated by subtracting the Year’s Maximum Pensionable Earnings for that year  —  multiplied by the number