California Expert WitnessVarious uncertainties have arisen in the legal field with respect to how and when to disclose and designate experts in California. This article addresses these matters and examines how to comply with the requirements of the California Code of Civil Procedure (C.C.P.), depending upon whether the expert witness is retained or non-retained.


Retained Experts: According to C.C.P. § 2034.210 (b), information about retained expert witnesses must be disclosed in a timely manner. To be considered timely, such information must be disclosed upon demand by an adverse party, once the case is filed and the initial trial date set. Id. Once a court has set a trial date, any party may demand information about the experts that any other party intends to have testify at trial, as well as “the production of all discoverable reports and writings that were made in the course of preparing the expert’s opinion.” Sacramento County Public Law Library, “Discovery: Exchange of Expert Witness Information,” available at (last visited Jun. 24, 2015).

Moreover, as the California Supreme Court explained: “Retained experts must be designated, and the designation must [further] be accompanied by the ‘expert declaration’…” Kalaba v. Gray, 95 Cal. App. 4th 1416, at 1422-1423 (2002). The expert declaration is an important component of the information attorneys must disclose to their opponents. One key element of the expert declaration is the narrative statement, which requires that attorneys provide a discussion of the “general substance the expert is expected to give.” See, e.g., Bonds v. Ray, 20 Cal. 4th 140, 146-47 (1990). One of the most common errors made by litigators is to fail to properly and sufficiently provide these narrative statements to opposing counsel. See Brian Chase, “Don’t Designate an ‘Inexpert’ Expert,” Advocate, Jul. 2011. Attorneys must furnish the information that they expect their experts to testify to at trial in the narrative statement, as failure to do so may have dire consequences. The California Supreme Court ruled that a retained expert’s testimony at trial cannot “exceed the scope of the description of the ‘narrative statement of the general substance the expert is expected to give,’ and is properly excluded on the motion of an adverse party.” Id. (citing Bonds v. Ray). Practitioners who either unwittingly or intentionally put an expert on the stand and attempt to exceed the scope of the original narrative statement face losing the ability to use the entirety of that expert’s testimony. See id., e.g.

In addition to the narrative statement, a proper expert witness declaration includes the expert’s name, address, contact information, and hourly rates for depositions and consultations.

Non-retained Experts: In the case of a non-retained expert who is expected to testify at trial, the disclosure procedures and requirements are markedly different. According to the C.C.P., once a proper request is made of an attorney, that party must disclose only a list of names and addresses of non-retained expert witnesses. See, e.g. C.C.P., § 2034.260 (b). The information the C.C.P. requires for a non-retained expert is intended to allow adverse parties to locate these witnesses and, if they wish, subpoena them for the purpose of deposing them. If improper or insufficient contact information is provided for a non-retained expert witness, that witness’s testimony may very well be excluded at trial, so practitioners should exercise diligence in providing their opponents with reliable and up-to-date information. See, e.g., Chase, supra


The duty of disclosure with respect to expert witnesses varies considerably, depending upon whether the expert is retained or not. In either event, California practitioners should be aware of the C.C.P. and use the correct procedures to properly disclose and designate their expert witnesses, thereby avoiding the penalties that the C.C.P. may impose for such oversights.

By: Kat S. Hatziavramidis, Attorney-at-Law