If, pending the action, the plaintiff assigns the cause of action, the assignee, upon written motion, may either be joined as a coplaintiff or be substituted as a sole plaintiff, as the judicial authority may order; provided that it shall in no manner prejudice the defense of the action as it stood before such change of parties.
Section 9-16.Assignment Pending Suit
Current through August 12, 2025 (2026 Practice Book edition) · Last verified July 9, 2026
In one sentenceIf a plaintiff assigns their entire claim while the lawsuit is already pending, the assignee can ask the court to be added as a coplaintiff or to take over as the sole plaintiff, without prejudicing the defense as it existed before the change.
Full Text of Section 9-16
Amendment History
(P.B. 1978-1997, Sec. 96.)
Plain-English Summary
This rule covers what happens when a plaintiff assigns the whole cause of action after filing suit. The assignee does not automatically step into the case. Instead, the assignee must file a written motion asking to be joined as a coplaintiff or substituted as the sole plaintiff.
The judicial authority decides which of those two options to order. Either way, the change of parties cannot prejudice the defense of the action as it stood before the assignment took place.
Frequently Asked Questions
What happens if a plaintiff assigns the claim while the case is pending?
The assignee may, upon written motion, be joined as a coplaintiff or substituted as the sole plaintiff, as the judicial authority may order.
Does the assignee automatically become the plaintiff?
No. The assignee must file a written motion, and the judicial authority decides whether the assignee is joined or substituted.
Can the substitution hurt the defendant's existing defenses?
No. The rule requires that the change of parties in no manner prejudice the defense of the action as it stood before the change.
Source & verification. The section text is reproduced verbatim from the
official Connecticut Practice Book (Conn. Practice Book § 9-16). Prescribed by the Judges of the Superior Court of Connecticut (Conn. Gen. Stat. Section 51-14). The plain-English summary is original and written by us. Last verified July 9, 2026. ·
Official source
Also known as: assignment of claim during lawsuitsubstituting assignee as plaintiff CTcoplaintiff after assignment pending actionwritten motion substitute plaintiff assignee