Key Takeaway
New York appellate court reinforces strict compliance with CPLR 3101(d) expert disclosure rules, precluding witnesses disclosed after trial began without explanation.
Expert witness disclosure rules under New York’s Civil Practice Law and Rules (CPLR) Section 3101(d) serve a critical function in civil litigation. These rules require parties to provide advance notice of expert witnesses, including their qualifications and the substance of their expected testimony. This procedural requirement ensures fair play and prevents trial by ambush, giving opposing counsel adequate time to prepare cross-examination and retain competing experts.
The Second Department’s recent decision in the Western Ramapo Sewer Extension Project case demonstrates the courts’ increasingly stringent approach to expert witness disclosure violations. While attorneys have historically seen some flexibility in enforcement, this ruling suggests that timing violations—particularly those occurring after trial commencement—face heightened scrutiny.
Jason Tenenbaum’s Analysis:
Matter of Western Ramapo Sewer Extension Project, 2014 NY Slip Op 05889 (2d Dept. 2014)
“The Supreme Court providently exercised its discretion in precluding two of the Sewer District’s witnesses from testifying at trial as experts, based upon its noncompliance with CPLR 3101(d)(1)(i) (see Rivers v Birnbaum, 102 AD3d 26; Sushchenko v Dyker Emergency Physicians Serv., P.C., 86 AD3d 638, 639; Mohamed v New York City Tr. Auth., 80 AD3d 677, 678; Parlante v Cavallero, 73 AD3d 1001, 1003). In this regard, the Sewer District did not disclose or identify either witness until after the trial had begun, and provided no explanation for that failure.”
Preclusion seems to be waning as to 3101(d) violations unless it occurs after the trial commenced.
Key Takeaway
The Second Department’s decision signals a potential shift in how courts handle CPLR 3101(d) violations. While minor disclosure defects during discovery may receive more lenient treatment, attorneys who fail to identify expert witnesses until after trial begins—without adequate justification—face near-certain preclusion. This underscores the importance of early case preparation and strict adherence to procedural requirements in expert witness cases.
Legal Update (February 2026): Since this post’s publication in 2014, New York courts have continued to refine the application of CPLR 3101(d) expert disclosure requirements, with subsequent appellate decisions potentially modifying the standards for preclusion remedies and timing compliance. Additionally, amendments to related discovery rules and evolving case law regarding expert witness testimony may have affected the procedural landscape discussed in this analysis. Practitioners should verify current CPLR provisions and recent judicial interpretations when handling expert disclosure matters.
