Key Takeaway
Court strikes expert affidavit when plaintiff failed to identify expert during discovery phase, emphasizing importance of timely disclosure under CPLR 3101(d).
This article is part of our ongoing discovery coverage, with 97 published articles analyzing discovery issues across New York State. Attorney Jason Tenenbaum brings 24+ years of hands-on experience to this analysis, drawing from his work on more than 1,000 appeals, over 100,000 no-fault cases, and recovery of over $100 million for clients throughout Nassau County, Suffolk County, Queens, Brooklyn, Manhattan, and the Bronx. For personalized legal advice about how these principles apply to your specific situation, contact our Long Island office at (516) 750-0595 for a free consultation.
Expert Disclosure Deadlines: A Costly Mistake in Discovery
New York’s Civil Practice Law and Rules require parties to identify expert witnesses during the discovery phase of litigation. CPLR 3101(d) specifically mandates that expert information be disclosed in response to proper discovery demands. When attorneys miss these deadlines, the consequences can be severe — as demonstrated in a recent Second Department decision that excluded a plaintiff’s expert entirely.
The timing of expert disclosure becomes particularly critical when parties file their note of issue and certificate of readiness, which signals to the court that discovery is complete. Once this milestone is reached, introducing new experts becomes significantly more difficult without compelling justification.
Jason Tenenbaum’s Analysis:
Lombardi v Alpine Overhead Doors, Inc., 2012 NY Slip Op 01590 (2d Dept. 2012)
“In opposition, the plaintiff failed to raise a triable issue of fact. Contrary to the plaintiff’s contention, the Supreme Court properly declined to consider his expert affidavit submitted in opposition to the defendant’s motion. The expert was not identified by the plaintiff until after the note of issue and certificate of readiness were filed attesting to the completion of discovery, and the plaintiff did not provide any excuse for failing to identify the expert in response to the defendant’s discovery demands (see CPLR 3101; Kopeloff v Arctic Cat, Inc., 84 AD3d 890, 890-891; Ehrenberg v Starbucks Coffee Co., 82 AD3d 829, 830-831; Gerardi v Verizon N.Y., Inc., 66 AD3d 960, 961).”
Key Takeaway
Courts will not consider expert affidavits when the expert was not properly disclosed during discovery, especially after the note of issue is filed. The plaintiff’s failure to provide any excuse for the delayed disclosure proved fatal to their opposition to summary judgment. This case underscores the importance of timely compliance with discovery obligations under CPLR 3101(d).
Legal Update (February 2026): Since this 2012 post, New York’s discovery rules under CPLR Article 31 have undergone various amendments, including modifications to expert disclosure requirements and timelines. Additionally, appellate decisions may have further clarified or modified the standards for expert exclusion and post-note of issue expert identification. Practitioners should verify current CPLR provisions and recent case law regarding expert disclosure deadlines and sanctions.
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Legal Context
Why This Matters for Your Case
New York law is among the most complex and nuanced in the country, with distinct procedural rules, substantive doctrines, and court systems that differ significantly from other jurisdictions. The Civil Practice Law and Rules (CPLR) governs every stage of civil litigation, from service of process through trial and appeal. The Appellate Division, Appellate Term, and Court of Appeals create a rich and ever-evolving body of case law that practitioners must follow.
Attorney Jason Tenenbaum has practiced across these areas for over 24 years, writing more than 1,000 appellate briefs and publishing over 2,353 legal articles that attorneys and clients rely on for guidance. The analysis in this article reflects real courtroom experience — from motion practice in Civil Court and Supreme Court to oral arguments before the Appellate Division — and a deep understanding of how New York courts actually apply the law in practice.
About This Topic
Discovery Practice in New York Courts
Discovery is the pre-trial process through which parties exchange information relevant to the dispute. In New York, discovery practice is governed by CPLR Article 31 and involves depositions, interrogatories, document demands, and physical examinations. Disputes over the scope of discovery, compliance with demands, and sanctions for noncompliance are frequent in both no-fault and personal injury cases. These articles analyze discovery rules, court decisions on discovery disputes, and strategies for effective discovery practice.
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Frequently Asked Questions
What is discovery in New York civil litigation?
Discovery is the pre-trial phase where parties exchange relevant information and evidence. Under CPLR Article 31, discovery methods include depositions (oral questioning under oath), interrogatories (written questions), document demands, requests for admission, and physical or mental examinations. Discovery in New York is governed by the principle of full disclosure of all relevant, non-privileged information — but courts can issue protective orders to limit discovery that is overly broad or burdensome.
What happens if a party fails to comply with discovery requests?
Under CPLR 3126, a court can impose penalties for failure to comply with discovery, including preclusion of evidence, striking of pleadings, or even dismissal of the action or entry of a default judgment. Before seeking sanctions, the requesting party typically must demonstrate a good-faith effort to resolve the dispute and may need to file a motion to compel disclosure under CPLR 3124.
What are interrogatories and how are they used in New York litigation?
Interrogatories are written questions served on the opposing party that must be answered under oath within a specified timeframe. Under CPLR 3130, interrogatories in New York are limited — a party may serve a maximum of 25 interrogatories, including subparts, without court permission. Interrogatories are useful for obtaining basic factual information such as witness names, insurance details, and factual contentions. Objections must be specific and timely or they may be waived.
What is a bill of particulars in New York personal injury cases?
A bill of particulars under CPLR 3043 and 3044 provides the defendant with the specific details of the plaintiff's claims — including the injuries sustained, the theory of liability, and the damages sought. In personal injury cases, it must specify each injury, the body parts affected, and the nature of the damages claimed. An amended or supplemental bill may be served to include new injuries or updated information discovered during the course of litigation.
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About the Author
Jason Tenenbaum, Esq.
Jason Tenenbaum is the founding attorney of the Law Office of Jason Tenenbaum, P.C., headquartered at 326 Walt Whitman Road, Suite C, Huntington Station, New York 11746. With over 24 years of experience since founding the firm in 2002, Jason has written more than 1,000 appeals, handled over 100,000 no-fault insurance cases, and recovered over $100 million for clients across Long Island, Nassau County, Suffolk County, Queens, Brooklyn, Manhattan, the Bronx, and Staten Island. He is one of the few attorneys in the state who both writes his own appellate briefs and tries his own cases.
Jason is admitted to practice in New York, New Jersey, Florida, Texas, Georgia, and Michigan state courts, as well as multiple federal courts. His 2,353+ published legal articles analyzing New York case law, procedural developments, and litigation strategy make him one of the most prolific legal commentators in the state. He earned his Juris Doctor from Syracuse University College of Law.
Disclaimer: This article is published by the Law Office of Jason Tenenbaum, P.C. for informational and educational purposes only. It does not constitute legal advice, and no attorney-client relationship is formed by reading this content. The legal principles discussed may not apply to your specific situation, and the law may have changed since this article was last updated.
New York law varies by jurisdiction — court decisions in one Appellate Division department may not be followed in another, and local court rules in Nassau County Supreme Court differ from those in Suffolk County Supreme Court, Kings County Civil Court, or Queens County Supreme Court. The Appellate Division, Second Department (which covers Long Island, Brooklyn, Queens, and Staten Island) and the Appellate Term (which hears appeals from lower courts) each have distinct procedural requirements and precedents that affect litigation strategy.
If you need legal help with a discovery matter, contact our office at (516) 750-0595 for a free consultation. We serve clients throughout Long Island (Huntington, Babylon, Islip, Brookhaven, Smithtown, Riverhead, Southampton, East Hampton), Nassau County (Hempstead, Garden City, Mineola, Great Neck, Manhasset, Freeport, Long Beach, Rockville Centre, Valley Stream, Westbury, Hicksville, Massapequa), Suffolk County (Hauppauge, Deer Park, Bay Shore, Central Islip, Patchogue, Brentwood), Queens, Brooklyn, Manhattan, the Bronx, Staten Island, and Westchester County. Prior results do not guarantee a similar outcome.