Within twenty days after service of the answer to the third-party complaint upon plaintiff’s attorney, the plaintiff may amend his complaint without leave of court to assert against the third-party defendant any claim plaintiff has against the third-party defendant.
R 1009.Claim by plaintiff against third-party defendant.
Article 10. Parties Generally · Last amended 1985 · Last verified July 21, 2026
In one sentenceCPLR 1009 gives the plaintiff twenty days after being served with the third-party defendant's answer to amend the complaint, without needing the court's permission, and assert a direct claim of its own against the third-party defendant.
Full Text of CPLR 1009
Plain-English Summary
Bringing in a third-party defendant under CPLR 1007 doesn't just create a dispute between the original defendant and the new party -- it can open the door for the plaintiff too. CPLR 1009 lets the plaintiff amend the complaint, without asking the court first, to assert a direct claim against the third-party defendant.
The rule sets a short window for that move: twenty days from when the third-party defendant's answer is served on the plaintiff's attorney. Once that clock starts, the plaintiff can decide whether the third-party defendant is someone worth suing directly, rather than leaving that dispute entirely between the original defendant and the newcomer.
The practical effect is to let the plaintiff build on work the defendant already did in bringing the third-party defendant into the case. Instead of starting a separate lawsuit against that party, the plaintiff can fold a direct claim into the case already underway, so long as it acts within the twenty-day window the rule sets.
Frequently Asked Questions
Can a plaintiff sue a third-party defendant directly in New York?
Yes. CPLR 1009 lets the plaintiff amend the complaint without leave of court to assert a direct claim against the third-party defendant.
How long does a plaintiff have to sue a third-party defendant under CPLR 1009?
The plaintiff has twenty days after the third-party defendant's answer is served on the plaintiff's attorney to amend the complaint and add a claim against that party.
Does the plaintiff need court permission to amend under CPLR 1009?
No. CPLR 1009 specifically allows the amendment without leave of court, as long as it's made within the twenty-day window the rule sets.
What happens if a plaintiff misses the twenty-day window in CPLR 1009?
The rule's text ties the automatic right to amend to that twenty-day period; a plaintiff who misses it would need to seek the court's permission to amend under the general amendment rules instead.
Why would a plaintiff want to sue a third-party defendant directly?
Once a defendant has brought in a third-party defendant who may share responsibility for the underlying harm, CPLR 1009 lets the plaintiff pursue that party directly in the same case rather than filing a separate lawsuit.
Advisory Committee Notes
CPLR 1007 and 1009 relate to the procedures of third-party practice, whereby, after defendant’s service of the third-party complaint, the plaintiff may amend his or her complaint to assert any claim the plaintiff may have against the third-party defendant. The existing provisions are imprecise in specifying the time frames and other details of the procedure by which the plaintiff may proceed, with full knowledge of all pleadings and without leave of court, to assert any claim he or she may have against the third-party defendant.
Therefore, the sentence of CPLR 1007 providing for service by defendant of a copy of the third-party complaint on plaintiff’s attorney would be amended to provide that such service be made simultaneously upon issuance for service of the third-party complaint upon the third-party defendant. CPLR 1009 would be amended to provide that service of the answer to the third-party complaint upon plaintiff’s attorney commences the 20-day period within which the plaintiff may properly amend the complaint without leave of court to assert any claim the plaintiff may have against the third-party defendant.
The clarification of these technical niceties of timeliness and service of pleadings is crucial to the preservation of plaintiff’s right to amend as of right his complaint so as to assert against the third-party defendant any claim which all relevant pleadings may give rise to.
These changes are not intended to affect existing or evolving decisional law with regard to whether or not the plaintiff’s cause of action against the third-party defendant is barred by an applicable statute of limitations.
This proposal is based upon recommendations made to the Advisory Committee by the Association of Justices of the Supreme Court.
This rule contains only slight verbal changes from the form of statement in CPA § 193-a.
Twenty-day provision added to conform to the time limitation governing amendment of pleadings as of right generally. See CPLR § 3025(a).
Provision relating to counterclaim transferred to CPLR § 1008.
Amendment History
Formerly § 1009, add, L 1962, ch 308; redesignated Rule 1009, L 1962, ch 315, § 1; amd, by Judicial Conference, 1972; amd, L 1984, ch 329, § 2, eff Jan 1, 1985.
Source & verification. Provision text, History, and Advisory
Committee Notes are reproduced verbatim from the Consolidated Laws of New York.
Last verified July 21, 2026.
· Official source
Also known as: CPLR 1009 New Yorkplaintiff claim against third-party defendantamend complaint to add third-party defendant New Yorktwenty days third-party defendant claimsuing third-party defendant directly New Yorkplaintiff third-party practice New Yorkimpleader plaintiff claim CPLR