N.Y. Civil Practice Law & Rules § 1007: When third-party practice allowed

§ 1007. When third-party practice allowed. (a) After the service of a

defendant's answer, the defendant may proceed against a person or legal

entity not a party who is or may be liable to that defendant for all or

part of the plaintiff's claim against that defendant, by filing pursuant

to section three hundred four of this chapter a third-party summons and

complaint with the clerk of the court in the county in which the main

action is pending, for which a separate index number shall not be issued

but a separate index number fee shall be collected. The third-party

summons and complaint and all prior pleadings served in the action shall

be served upon such person or legal entity within twenty days of the

filing. A defendant serving a third-party complaint shall be styled a

third-party plaintiff and the person or legal entity so served shall be

styled a third-party defendant. The defendant shall also serve a copy of

such third-party complaint upon the plaintiff's attorney simultaneously

upon issuance for service of the third-party complaint on the

third-party defendant.

(b) A defendant shall not file a third-party summons and complaint

more than ninety days after serving its answer without an order of the

court.

(c) No third-party summons and complaint may be filed after the filing

of a note of issue unless upon good cause shown or in the interest of

justice.

(d) An action filed in violation of this subdivision shall be severed

or dismissed without prejudice.

(e) Notwithstanding subdivisions (b) and (c) of this section, a

defendant or third-party defendant may file a third-party summons and

complaint against an employer of the plaintiff without an order of the

court within ninety days after the later of: 1. the date the identity of

the employer of the plaintiff becomes known to the defendant or

third-party defendant, or 2. the date the defendant or third-party

defendant knows or should know the plaintiff sustained a grave injury,

as such term is defined in section eleven of the workers' compensation

law.

(f) In the event a third-party action is severed from the initial

action pursuant to this section, and a third-party plaintiff proceeds to

initiate a new action by the filing of a summons and complaint against a

severed third-party defendant, any motion to consolidate such actions

shall not be permitted.