Key Takeaway
NY court rules CPLR 3101(d) expert disclosure violation doesn't require automatic preclusion without showing willfulness or significant prejudice to opposing party.
Understanding CPLR 3101(d) Expert Disclosure Violations
Civil Practice Law and Rules (CPLR) 3101(d) requires parties to provide timely disclosure of expert witnesses and their expected testimony. However, New York courts don’t automatically exclude expert testimony when this rule is violated. Instead, courts apply a balanced approach that examines whether the violation was willful and whether it caused significant prejudice to the opposing party.
This distinction is crucial in litigation strategy. While expert testimony can be pivotal to a case’s outcome, courts recognize that technical disclosure violations shouldn’t automatically derail otherwise valid expert opinions. The Second Department’s recent decision in State of New York v Dennis K. reinforces this principle, demonstrating that even substantial disclosure failures may not warrant preclusion if certain conditions aren’t met.
The court’s analysis focuses on two key factors: the intent behind the violation and the actual harm suffered by the opposing party. This approach balances the need for procedural compliance with the fundamental goal of reaching decisions based on the merits rather than technicalities.
Jason Tenenbaum’s Analysis:
Matter of Matter of State of New York v Dennis K., 2014 NY Slip Op 05884 (2d Dept. 2014
“The Supreme Court did not err in denying the appellant’s application to preclude certain expert testimony at the dispositional hearing, based on the State’s failure to comply with CPLR 3101(d), as no wilfulness or significant prejudice was demonstrated (see Ocampo v Pagan, 68 AD3d 1077, 1078; Shopsin v Siben & Siben, 289 AD2d 220, 221).”
A wholesale violation of the statute does not require preclusion.
Key Takeaway
Courts will not automatically exclude expert testimony for CPLR 3101(d) violations unless the moving party demonstrates both willfulness and significant prejudice. Even substantial disclosure failures can be overcome if these two critical elements are absent, allowing expert evidence to be considered on its merits rather than being excluded on procedural grounds alone.
Legal Update (February 2026): Since this 2014 post, CPLR 3101(d) expert disclosure requirements and judicial interpretation of violation remedies may have evolved through subsequent court decisions and procedural amendments. Practitioners should verify current provisions regarding expert witness disclosure deadlines, required content of disclosures, and judicial standards for determining willfulness and prejudice in violation cases.
