D.C. Code § 38-2023.13
The amendment made by Pub. L. 96-122, §251(a)(1), to § 38-2021.21(b) shall apply to any increase after the effective date of such amendment in annuities payable from the District of Columbia Teachers' Retirement and Annuity Fund established by § 38-2021.02 or from the District of Columbia Teachers' Retirement Fund established by § 1-713(a), except that with respect to the first date after the effective date of such amendment on which the Mayor is to determine a per centum change, such per centum change shall be determined by computing the change in the price index published for the month immediately preceding such 1st date over the price index published for the last month before such effective date for which the price index showed a per centum rise forming the basis for a cost-of-living annuity increase under § 38-2021.21(b), as in effect immediately before the amendment of such section by Pub. L. 96-122, §251(a)(1).
D.C. Code § 38-2023.13