Group IV: Parties · Last amended 2017 · Last verified July 14, 2026
This rule is substantially similar to Federal Rule of Civil Procedure 24, as amended in 2007, but maintains the following local distinctions: 1) the addition of “District of Columbia” in subsection (b)(2); and 2) the substitution of “applicable law” for “federal statute” throughout the rule.
As with the federal rule, the notification provisions for challenges to the constitutionality or validity of 1) federal or state statutes, or 2) acts, orders, regulations, or enactments exclusively applicable to the District of Columbia, which were formerly found in section (c), have been moved to Rule 5.1.
Rule 24 identical to Fed. Rule of Civil Procedure 24 except for (1) addition of "District of Columbia" to the governmental jurisdictions specified in the 2nd sentence of section (b); (2) substitution of "applicable law" for "statute of the United States" in sections (a), (b), and (c) so as to comprehend reference to appropriate statutory or case law relating to intervention rights in the District of Columbia.; and (3) addition to section (c) of a notification provision for acts, orders regulations, or enactments exclusively applicable to the District of Columbia so that this Court will follow as nearly as possible the notification procedure prescribed for courts of the United States in 23 U.S.C. § 2403. In order to assist the Court in fulfilling its notification responsibilities under this section, the Rule requires an alerting inscription on every pleading the filing of which makes such notification necessary.
The District of Columbia Self-Government and Governmental Reorganization Act of 1973, Public Law 93-198, is reported in its entirety in Volume 1 of the 1981 Michie Edition of the D.C. Code (1991 Replacement Volume, pp. 173-255). Individual sections of the Act are codified throughout the D.C. Code, and a listing of those sections and references to their counterparts in the D.C. Code can be found in the Disposition Table in Volume 11 of the 1981 (1990 Replacement Volume, pp. 216-218).
Rule 24(a) covers intervention of right: on timely motion, the court must let someone into the case who has an unconditional right to intervene under applicable law, or who claims an interest in the property or transaction at issue and is positioned such that resolving the case without them could, as a practical matter, hurt their ability to protect that interest — unless the parties already in the case adequately look out for it. Because this branch of the rule is mandatory once its conditions are met, timeliness of the motion matters: a movant who waits too long risks losing the right to intervene even if its interest is otherwise exactly the kind the rule protects.
Rule 24(b) covers permissive intervention, which rests in the court's discretion. The court may allow someone in who has a conditional right to intervene under applicable law, or whose claim or defense shares a common question of law or fact with the main action. It may also allow a federal, District of Columbia, or state government officer or agency to intervene when a party's claim or defense is based on a statute or executive order that officer or agency administers, or on a regulation, order, requirement, or agreement issued under it. For this permissive route, the court must also consider whether letting the newcomer in will unduly delay or prejudice the existing parties' case — a factor that has no counterpart in the mandatory intervention-of-right branch under Rule 24(a).
Rule 24(c) sets the mechanics: a motion to intervene is served on the parties the same way any motion is served under Rule 5, must state the grounds for intervening, and must come with a pleading setting out the claim or defense the intervenor wants to raise — so the court and the existing parties can see precisely what the newcomer would add before deciding whether to let it in.
Under Rule 24(a), the court must allow intervention when an applicable law gives an unconditional right to intervene, or when the movant's interest in the case could be impaired without adequate protection from the existing parties. Under Rule 24(b), the court has discretion to allow intervention based on a conditional legal right or a claim or defense sharing a common question with the case.
Yes. Rule 24(b)(2) lets the court permit a federal, District of Columbia, or state government officer or agency to intervene when a party's claim or defense is based on a statute or executive order that agency administers, or on a regulation, order, requirement, or agreement issued under it.
Rule 24(c) requires the motion to be served on the parties under Rule 5, to state the grounds for intervening, and to be accompanied by a pleading that sets out the claim or defense for which intervention is sought.
Delay is a factor the court weighs, not an automatic bar. Rule 24(b)(3) requires the court to consider whether intervention will unduly delay or prejudice the adjudication of the original parties' rights, alongside the other requirements for permissive intervention.
Not as a matter of right. Rule 24(a)(2) requires that existing parties not already adequately represent the movant's interest before intervention of right is available, though permissive intervention under Rule 24(b) may still be possible if there is a shared common question.