(a) INTERVENTION OF RIGHT. On timely motion, the court must permit anyone to intervene who: (1) is given an unconditional right to intervene by an applicable law; or(2) claims an interest relating to the subject of the action, and is so situated that disposing of the action may as a practical matter impair or impede the movant's ability to protect its interest, unless existing parties adequately represent that interest.(b) PERMISSIVE INTERVENTION. (1)In General. On timely motion, the court may permit any person to intervene who: (A) is given a conditional right to intervene by an applicable law; or(B) has a claim or defense that shares with the pending action a common question of law or fact.(2)Delay or Prejudice. In exercising its discretion, the court must consider whether the intervention will unduly delay or prejudice the adjudication of the original parties' rights.(c) NOTICE AND PLEADING REQUIRED. A motion to intervene must be served on the parties as provided in Rule 5. The motion must state the grounds for intervention and be accompanied by a pleading that sets out the claim or defense for which intervention is sought.COMMENT TO 2018 AMENDMENTS
This rule has been modified to conform to Civil Rule 24. In accordance with amendments to the civil rules, 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 (d), have been moved to Rule 5.1.
In section (b), the reference to "governmental entity" was deleted as unnecessary and potentially confusing because the term "person" as used in other rules includes entities-both governmental and private. Section (b) differs from the corresponding civil provision, which specifies under what circumstances the court may permit governmental intervention.