D.C. Code § 1-602.06
Supersession provisions; effectiveness of collective bargaining on compensation matters.
On the date that the provisions of § 1-617.16 become operational and negotiations commence concerning compensation matters, all employees of the District government in the appropriate bargaining units under § 1-617.16 , including those described in § 1-602.04 , shall be subject to the procedures and provisions for establishing compensation provided in § 1-617.16 : Provided, however, that no employee subject to the provisions of § 1-602.04 shall be reduced in actual pay, except in accordance with the provisions of subchapter XXIV of this chapter .