Massachusetts Rules Regarding Expert Witness Depositions and Interrogatories 

There is no general right to depose expert witnesses in Massachusetts, even those that are expected to testify at trial. However, Rule 26(b)(4)(A)(ii) of the Massachusetts Rules of Civil Procedure provides that, upon motion, a court may order discovery beyond the generally allowed means, discussed in the following section, which may include deposition. Also, experts generally may not be subject to interrogatories in Massachusetts, as they are only served on the parties. As discussed in the following section, though, these interrogatories can require disclosures about experts and, accordingly, expert participation in responding to certain interrogatories may be beneficial. 

Massachusetts Expert Witness Reports and Disclosures Rules 

The extent of required disclosures for experts in Massachusetts depends on whether the expert is expected to testify at trial or was retained only for consulting purposes. For the latter category of experts, Rule 26(b)(4)(B) of the Massachusetts Rules of Civil Procedure provides that discovery may only be had upon a showing of exceptional circumstances under which it is impracticable for the party seeking discovery to obtain facts or opinions on the same subject by other means.

For an expert expected to be called at trial, Rule 26(b)(4)(A)(i) provides that a party can be required to disclose the identity of such expert, the subject matter on which he or she is expected to testify, the substance of the facts and opinions to which the expert is expected to testify, and a summary of the basis for these opinions upon interrogatory from the opposing party. Again, under Rule 26(b)(4)(A)(ii), discovery by more intrusive means, such as a document production request, may be had upon motion. See, e.g., O’Brien v. Am. Med. Response of Mass., 2013 Mass. Super. LEXIS 131, at *10-12 (Mass. Super. Ct., Sept. 12, 2013) (granting a motion for further expert discovery despite that fact the interrogatories concerning the expert were properly completed, because “the expert’s opinions [could not] be adequately and fairly disclosed without production . . . of the actual computer simulation the expert expects to use in testimony,” “the name of the software program” on which the computer simulation was run, and “any and all documents which were used as input into the computer simulation”). 

Rules Regarding Lawyer-Expert Communications, Draft Expert Witness Reports, Expert Witness Notes, Etc. in Massachusetts 

As the O’Brien case cited above makes clear, document production requests can reach well beyond just the final report of the expert. This reach is not unlimited, though. Discovery of attorney-expert communications that occurred prior to the production of the expert’s report is restricted to information considered by the expert in furnishing the report. All other attorney-expert communications occurring as part of the creation of the report, including preliminary and draft reports, are considered trial preparation material. Trial preparation material is governed by Rule 26(b)(3) of the Massachusetts Rules of Civil Procedure, and can only be discovered upon a showing that the party seeking discovery has substantial need for the materials and is unable to obtain the substantial equivalent of the materials by other means without undue hardship. See also LN Practice Guide MA Civil Pretrial Practice § 7.24, Discovering Communications Between Expert and Attorney (2014).