If a party has timely served a Demand for Simultaneous Exchange of Expert Trial Witness Information pursuant to Code of Civil Procedure section 2034.210, then “all parties who have appeared in the action shall exchange information concerning expert witnesses in writing on or before the date of exchange specified in the demand.”C.C.P. §2034.260(a). Unless there is a court order specifying otherwise, that date for the simultaneous exchange is 50 days before the initial trial date, or 20 days after service of the demand, whichever is closer to the trial date. C.C.P. §2034.230(b).

The information that is exchanged must be in compliance with C.C.P. §2034.260(b) and (c) which states:

(b) The exchange of expert witness information shall include either of the following:

(1) A list setting forth the name and address of a person whose expert opinion that party expects to offer in evidence at the trial.

(2) A statement that the party does not presently intend to offer the testimony of an expert witness.

(c) If a witness on the list is an expert as described in subdivision (b) of Section 2034.210, the exchange shall also include or be accompanied by an expert witness declaration signed only by the attorney for the party designating the expert, or by that party if that party has no attorney. This declaration shall be under penalty of perjury and shall contain all of the following:

(1) A brief narrative statement of the qualifications of each expert.

(2) A brief narrative statement of the general substance of the testimony that the expert is expected to give.

(3) A representation that the expert has agreed to testify at the trial.

(4) A representation that the expert will be sufficiently familiar with the pending action to submit to a meaningful oral deposition concerning the specific testimony, including an opinion and its basis, that the expert is expected to give at trial.

(5) A statement of the expert’s hourly and daily fee for providing deposition testimony and for consulting with the retaining attorney.

An expert witness declaration is required for each expert “retained by a party,” not just the designated party. In other words, if you are relying on another party’s expert (i.e., a co-defendant) you must still furnish an expert witness declaration for that expert. See Zellerino v. Brown (1991) 235 CA3d 1097, 1116. .

Treating physicians must be listed pursuant to C.C.P. §2034.260(b)(1), but do not require declarations as they are not retained. A treating physician does not become a “retained” expert within the meaning of C.C.P. 2034.210(b)simply because the physician will be called to provide expert testimony.  California Civil Discovery Practice (CEB 2020) §11.20 citing Schreiber v. Estate of Kiser (1999) 22 C4th, 31, 35. Nonetheless, if you do not specifically list the non-retained expert, the court may exclude the testimony. Kalaba v. Gray (2002) 95 CA4th 1416, 1418.  However, if a party gives the treating physician additional information to review for the physician’s testimony that was outside of the physician/patient relationship, then the treating physician becomes a retained expert and a C.C.P. §2034.260(c) declaration is required. See Schreiber v. Estate of Kiser, supra.

Code of Civil Procedure §2034.210(b) requires that “if any expert designated by a party under subdivision (a) is a party or an employee of a party or has been retained by a party for the purpose of forming and expressing an opinion in anticipation of the litigation or in preparation for the trial of the action, the designation of that witness shall include an expert witness declaration under Section 2034.260.”  For example, if a company has a lab or product manager that performed tests for warranty purposes that is expected to offer opinions at trial, counsel should be sure to include a declaration that the expert witness is a party’s employee.

In preparing the declaration you need to provide the following information for each expert you are disclosing so opposing counsel can determine the credibility of the expert, whether to depose the expert and whether to supplement their own expert disclosure:


It is important that you list the following areas or attach your expert’s resume to the declaration outlining your expert’s:

  • Area of expertise.
  • Relevant education.
  • Relevant employment and experience.
  • Professional society memberships, publications, and honors.

General substance of expected testimony

In determining what information you need to provide, Bonds v. Roy (1999) 20 C4th 140 at 146-147 gives the best guidance:

“…the very purpose of the expert witness discovery statute is to give fair notice of what an expert will say at trial. This allows the parties to assess whether to take the expert’s deposition, to fully explore the relevant subject area at any such deposition, and to select an expert who can respond with a competing opinion on that subject area. “The opportunity to depose an expert during trial, particularly if the testimony relates to a central issue, often provides a wholly inadequate opportunity to understand the expert’s opinion and to prepare to meet it. [Citations.]” (Kennedy & Martin, Cal. Expert Witness Guide, supra, § 10.18, at p. 267.) “[T]he need for pretrial discovery is greater with respect to expert witnesses than it is for ordinary fact witnesses [because] . . . the other parties must prepare to cope with witnesses possessed of specialized knowledge in some scientific or technical field. They must gear up to cross-examine them effectively, and they must marshal the evidence to rebut their opinions.” (1 Hogan & Weber, Cal. Civil Discovery (1997) Expert Witness Disclosure, §10.1, p. 525.)”

Remember, a party is not permitted to offer expert testimony at trial on undisclosed subjects.  See McCoy v. Gustafson (2009) 180 CA4th 56, 95-98

Representation that expert be ready to testify

The expert witness declaration is for counsel to guarantee that the experts are in fact retained and ready to testify. Prior to the 1986 Discovery Act, counsel was not required to give such assurances and could list numerous experts only for opposing counsel to find out at the expert’s deposition which designated expert was really going to testify.

Fees and Costs

The expert is entitled to charge their regular rate for deposition work, provided it a reasonable fee. However, the expert cannot charge a higher rate than what he charged his own client. See C.C.P. §2034.430(d) and Rancho Bernardo Development Co v. Superior Court (1992) 2 CA4th 358, 363.

BEWARE: failure to meet the statutory requirements regarding your expert disclosure can lead to your expert being stricken and barred from testifying.

California Civil Discovery Practice (CEB 2020) has a form titled Written Exchange of Required Expert Witness Information; Expert Witness Declaration at §11.70.