NY CPLR 3101(d) governs, among other things, the exchange of expert disclosures in litigation. However, the equivocal language within the CPLR as currently written leads to inconsistency, surprise, and disadvantage in practice.

NY CPLR 3101(d)(i) states, "Upon request, each party shall identify each person whom the party expects to call as an expert witness at trial and shall disclose in reasonable detail the subject matter … However, where a party for good cause shown retains an expert an insufficient period of time before the commencement of trial to give appropriate notice thereof, the party shall not thereupon be precluded from introducing the expert's testimony at the trial solely on grounds of noncompliance with this paragraph. In that instance, upon motion of any party, made before or at trial, or on its own initiative, the court may make whatever order may be just."

Lawsuits follow a logical course of discovery. The complaint asserts the elements of the cause of action, the Bill of Particulars amplifies the claims made in the complaint to a higher level of specificity, and the expert disclosure underlines the specific testimony and theories to be addressed at trial.