Expert Witness Disclosure: Litigation & Consulting Professionals


Expert Witness or Consultant

An expert witness disclosure is required if the expert is retained to testify at trial.  However, consulting expert disclosures, or additional disclosures of testifying experts are protected, such as the expert’s reports and depositions to be conducted.  Hence, absence of a showing of special or unusual circumstances a court order is required.

Rules of an expert witness disclosure apply only to testifying experts

Expert Witness Disclosure is Required if Testifying at Trial.

Expert Witness & The Treating Physician

In addition, different rules for expert witness disclosure apply to medical malpractice cases, for treating and examining physicians. That is, the rules differ depending on whether the retained expert witnesses are for plaintiff or defendant.  For instance, the plaintiff does not have to provide expert disclosures as to their medical treating expert because they are deemed to be fact witnesses. Instead, the plaintiff is required to provide copies of all relevant medical records, and examinations.  On the other hand, the defendant must provide disclosures of their medical expert who examined the plaintiff, and a copy of the report as well.


Although, the plaintiff would subpoena defendant’s expert to testify as part of plaintiff’s case in chief, defendant can also call the examining medical expert to testify about the Independent Medical Examination (IME) conducted to determine the cause, extent, and medical treatment of the plaintiff’s injury. If not, the defendant may be subject to a charge.  Additionally, the defendant must provide the plaintiff with a copy of plaintiff’s hospital records that they obtained.

Disclose or Not Disclose

The general rule for expert witness disclosure requires that such disclosure is conditional upon request and the party requesting the disclosure must identify each expert whom the party expects them to testify at trial.  The request may be independent as its own separate discovery petition or it could be included in a discovery request, asking for information about witnesses, parties’ statements, photographs, and more.

Rules of an Expert Witness Disclosure Apply Only to Testifying Experts

Rules of an Expert Witness Disclosure Apply Only to Testifying Experts

Disclosure Report

Further, such expert witness disclosure should set out the nature and relevance of the expert’s testimony.  Besides, the disclosure should be limited to the matter of the expert witness facts, and a summary of information for their opinions.  The reports should be protected from disclosure. Similarly, the expert witness disclosure about his qualifications, can be satisfied by providing the expert’s general information, such as their curriculum vitae; including the expert’s occupation, field of expertise, years of experience, and membership of professional organizations.

Finally, as regards the timing of expert witness disclosure, the Court looks at the length of time between hiring the expert and disclosing of the expert’s information; placing the burden on the proffering party to justify the late disclosure.  Therefore, the issue for failure to provide disclosure is whether the party’s delay was intentionally or willfully; and thus, the late disclosure and retention of the expert witness should be explained.

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