D.C. Mun. Regs. tit. 27, § 1615
1615.1 When, either before or after receipt of proposals, the District increases, decreases, or otherwise changes its requirements, the contracting officer shall issue a written amendment to the solicitation in accordance with §1607.
1615.2 In deciding which firms to notify of a change, the contracting officer shall consider the state in the procurement cycle at which the change occurs and the magnitude of the change, as follows:
(a) If proposals are not yet due, the amendment shall be sent to all firms that have received a solicitation;
(b) If the time for receipt of proposals has passed but proposals have not yet been evaluated, the amendment shall be sent only to the responding offerors; and
(c) If the competitive range has been established, the amendment shall be sent only to those offerors within the competitive range.
1615.3 If a change is so substantial that it warrants complete revision of a solicitation, the contracting officer shall cancel the original solicitation and issue a new one, regardless of the state of the procurement. The new solicitation shall be issued to all firms originally solicited and to any firms added to the original list, and shall be advertised in accordance with the requirements of this title.
1615.4 If the proposal considered to be most advantageous to the District (as determined by using the established evaluation criteria) involves a departure from the stated requirements, the contracting officer shall provide all offerors an opportunity to submit new or amended proposals on the basis of the revised requirements, if this can be done without revealing to the other offerors the solution proposed in the original departure or any other information that is entitled to protection.
SOURCE: Final Rulemaking published at 35 DCR 1455 (February 26, 1988).