Responding to Discovery Requests Directed to Expert Witnesses

WDC Journal Edition: Winter 2016
By: Kimberly Poyner and Gabriel Houghton, Ryan Law Firm LLC


Civil litigation is often described as a battle of experts. Increasingly, plaintiffs’ counsel are employing discovery methods not expressly authorized by statute in an effort to procure evidence of expert bias. Subpoenas duces tecum, for example, are being used to obtain documents and information directly from defense experts.

Under Wis. Stat. § 804.01(2)(d), interrogatories asking a party to identify their experts, and depositions to investigate the “facts known and opinions held” by them, are allowed.1 Prior to the 1995 revision of the statute, only interrogatories were authorized.2 If “further discovery by other means” was desired, a party was required to file a motion.3

The practice, however, was to conduct discovery without involving the court by agreement of the parties. These agreements would generally consist of the date, time, and place of the expert’s deposition, and who was to pay the expert’s fee. Usually, also by agreement, the expert’s file would be produced.

The rule eventually changed to reflect the practice. One question that now presents itself is whether documents outside the expert’s file must be produced when they are subpoenaed. The document production portion of the subpoena may include 1099 tax forms and a list of prior testimony similar to that required by Fed. R. Civ. P. 26(a)(2)(B).4 The percentage of income that the expert derives from litigation work and an expert’s prior reports may also be included in the demand.5 Since these documents may tend to suggest an expert’s bias towards a particular side, they arguably fit within the broad criterion that requests be “reasonably calculated to lead to the discovery of admissible evidence.”6

This Article first sets forth a number of legal and tactical arguments for counsel to consider when confronted with overly intrusive discovery demands. It then acknowledges the circumstances in which discovery demands for an expert’s financial information are appropriate. Finally, the Article closes by offering several tips for dealing with these demands.

Inappropriate Discovery Demands to an Expert Witness

There are several legal arguments and tactical decisions that can be made in opposing a subpoena duces tecum directed to one’s expert. This section discusses some of the most useful approaches.

A. The Nuclear Option

Often, both sides hire experts. Nearly as often as that, both experts are familiar with writing reports and providing testimony for one side or the other in a lawsuit. Under the venerated trope “what’s sauce for the goose is sauce for the gander,” any attorney who issues a subpoena demanding an expert’s personal financial information, or reports written for prior cases, should understand that the same demands will be made of his expert. The resulting skirmish may be detrimental to both parties. Adversaries should be aware that “what goes around comes around.”

B. Konle, Court Involvement, and Procedural Limits

Furthermore, there are limits on the amount of financial information from tax returns that needs to be provided in discovery. Even a plaintiff in a personal injury action claiming loss of income is not required to disclose his or her complete income tax returns without the court’s approval.7 In Konle v. Page, the Wisconsin Court of Appeals held that an in-camera inspection of the plaintiff’s records by the circuit court is the “best and proper procedure through which to filter such discovery demands.”8

A trial court has statutory authority under Wis. Stat. § 804.01(3) to limit disclosure of information in order “to protect a party or person from annoyance, embarrassment, oppression, or undue burden or expense.”9 Moreover, the statutes specifically set forth procedures for quashing or modifying a subpoena for the same reasons.10 Though Wisconsin courts have not directly addressed the question of whether an expert’s personal financial information is discoverable, Konle provides some insight into what they might do, and jurisdictions with procedural rules like Wisconsin’s have held that such inquiries directed to expert witnesses must be authorized by a court order.11 In Primm v. Isaac, for example, the Kentucky Supreme Court acknowledged the relevance of an expert’s professional activities to uncovering possible bias, but stated that merely because such activities may be relevant “does not mean that parties are entitled to unfettered discovery of impeachment evidence by whatever means they seek.”12 These courts recognize that the liberal discovery provisions that apply to parties to the lawsuit and other lay witnesses were not meant to pertain to nonparty expert witnesses.13

C. The Plain Language of Wisconsin’s Discovery Statutes

Wisconsin Stat. § 804.01(2)(d), by its plain language, arguably limits the available procedures for conducting expert discovery to interrogatories and depositions. Only upon motion may the court “order discovery by other means.”14

The balance that is achieved in the discovery statutes is the product of competing interests. On the one hand, there is the party’s legitimate need to investigate all avenues that may be relevant to the case, including an expert’s potential bias, and on the other hand, individuals have a right to be free of intrusive and harassing discovery demands.

A person may be compelled to answer written interrogatories, and to sign those answers under penalty of perjury, but interrogatories can only be served on parties to the lawsuit.15 Parties can be sent requests for documents and demands to enter upon land.16 A separate action may also be started to compel non-parties to do the same.17 Further, a party may be forced to admit or deny the most difficult and salient facts under Wis. Stat. § 804.11, and be subject under that statute to pay actual costs and attorney fees if reasonable inquiry is not made prior to the answer being made, but this statute does not allow these same requests to be sent to a nonparty.

Subpoenas can compel a nonparty to testify and/or to provide documents.18 Attorneys, as officers of the court, have been granted the authority to issue subpoenas.19 That authority, however, is kept in check by the opposing attorney’s right to move the court to modify or quash the subpoena.20

The Wisconsin Supreme Court was certainly aware of all of these discovery vehicles when, through our legislature, it amended Wis. Stat. § 804.01(2)(d) to allow for expert depositions without leave of the court.21 Instead of authorizing parties to use any discovery method they wish to employ to obtain information about an expert, the court chose to treat expert witnesses differently than non-expert, nonparty witnesses. If counsel requires certain documents, the trial court has within it authority to order said production. Without first receiving a stipulation from opposing counsel, or the imprimatur of the court, however, it would appear counsel does not have the right to employ any discovery method he chooses.22

D. Wisconsin’s Rules Contrasted with the Federal Rules of Civil Procedure

The Federal Rules of Civil Procedure mandate that a party identify any expert witness they intend to call at trial, and provide their written reports without awaiting a formal discovery request.23 The report must contain a variety of information, including a “complete statement” of all opinions the expert will express, the facts or data that underlie those opinions, background information about the witness’s prior testimony, and how much he was paid for his work on the case.24 The rather broad federal rule is rooted in the idea that the facts considered by an expert in forming his opinion are not considered work product.25

Fed. R. Civ. P. 26(a)(2)(B), however, has not been adopted in Wisconsin. There is no similar requirement to produce documents in our state’s statutes. The omission of such mandatory disclosures is significant. Under the canon of construction expressio unius est exclusio alterius, because Wisconsin’s statutes omit these mandatory disclosures, there is an argument that they are not required.26 If Wisconsin intended to follow the Federal Rules, these requirements could easily have been included in Wis. Stat. § 804.01(2)(d) when that statute was amended in 1995.

E. Chilling Effect

Courts may also be persuaded by the argument that requiring experts to disclose personal financial information may have a chilling effect on a party’s ability to retain high-quality experts.27 Those who have published articles in distinguished journals, taught at prestigious universities, and are recognized authorities in their chosen field may shy away from the rough and tumble of litigation when it means not merely defending their opinions, but also producing their tax records. The adversarial system, however, often requires experts’ participation in order for the factfinders to be able to render just verdicts.28

The danger of a chilling effect on experts’ willingness to participate in the litigation process may outweigh the probative value of the expert’s personal financial information.29 The mere fact of compensation, even for experts whose main source of income comes from litigation work, lacks probative force when cross-examination is sufficient to reveal whether an expert is “consistently chosen by a particular side in personal injury cases to testify on its respective behalf.”30

F. Slippery Slope

Courts may also be persuaded to limit overly broad discovery requests to expert witnesses because of the door such requests could open to collateral issues. As any litigator knows, sometimes what is produced is neither accurate nor complete.

Accordingly, since discovery begets discovery, a subpoena for an expert’s prior reports may lead to additional depositions and, perhaps, a trial prolonged with inquiries into an expert’s bias that have no bearing on the substantive issues. If prior reports from other cases are produced, the similarity or dissimilarity between such cases may have to be explained by the expert at trial in order to prevent the jury from getting an impression that the expert does not want to provide. In short, a trial within a trial may ensue.

Extensive probing of an expert’s financial circumstances may only confuse and distract the jury without having any relation to the issues the jury is to decide. Because both sides will likely be producing the same type of information for their respective experts, what should be a sideshow to expert testimony may end up being the marquee attraction. Of course, in addressing these issues, one must factor in the increased cost of litigation, which, by anyone’s estimate, is already too expensive.

Appropriate Financial Discovery

Notwithstanding the arguments outlined above, information may rightly be discoverable in order to expose a perversion of the system. For example, take the case of a medical provider who routinely treats a substantial number of plaintiffs from a particular law firm. The settlement or verdict that is reached fails to satisfy the provider’s lien, yet a review of public records indicates that the provider never sues the plaintiffs to collect the remainder of the bills. One might conclude that some “arrangement” exists between the law firm and the provider. Financial information in such a case is essential to uncover the truth behind these questionable dealings.

Similarly, if there is an indication that medical specials have been artificially enhanced by diagnostic testing, or there has been an “unbundling” of services in contravention of the CPT codes,31 then financial information will likely be necessary to establish any irregularities. The point is that, when counsel makes “a strong showing that the witness has been evasive or untruthful,” a court may order further disclosures.32

Nevertheless, the argument that overly intrusive demands for an expert’s personal financial information will have a chilling effect is often persuasive. The reality is that both plaintiffs and defendants depend on experts. If experts of high repute are compelled to disclose their personal data, many would refuse to participate in litigation to the detriment of both sides.33

Practice Pointers

When your expert is served with a subpoena, the first thing to do is find out what is being demanded. Then ask your expert what, if anything, they do not want to produce. Uniformity from one’s experts on this question is necessary to prevent an allegation that one expert is being unreasonable in light of another expert’s willingness to produce the documents. The demand that is the least objectionable to all of one’s experts will provide the proverbial line in the sand.

The next step is to call opposing counsel. Try to reach a compromise about the scope of materials that must be provided. Be sure to convey your position on the scope of expert discovery to counsel in writing.

Trying to reach an agreement with opposing counsel is important for two reasons. First, the trial court may dislike becoming involved in discovery disputes, and local court rules often mandate that parties make a sincere effort to resolve such disputes before bringing a motion. Second, if all counsel is asking for is your expert’s file and invoices for the current case, it may not be worth arguing about. A trial court would likely require disclosure of these particular documents in any event.

If, after your best efforts, a compromise is not achievable, counsel should file a motion to quash under Wis. Stat. § 805.07(3). It is desirable to have some minor measure of control over the motion by being the movant instead of the respondent. The letter setting forth your willingness to compromise should be included by way of an exhibit to counsel’s affidavit. Objections to specific demands in the subpoena should be set forth. Arguments based on procedural grounds and/or policy considerations, some of which have been discussed in this Article, should be made succinctly and with verve. Counsel should also emphasize that the court’s order withregard to what must be produced should apply to both parties’ experts with equal force without requiring the moving party to issue its own subpoenas.


Subpoenas directed to experts broadly requesting their personal financial information may not be allowed under the statute, may offend the sensibilities of the experts, and may result in a chilling effect on highly-qualified experts’ willingness to participate in litigation. Steps should be taken, therefore, to protect one’s experts from unreasonably intrusive demands by opposing counsel.

Nevertheless, under certain circumstances it may be appropriate to compel the disclosure of financial information. As noted above, when financial records likely contain evidence of questionable dealings, or even nefarious activity, then a much stronger argument exists for their production. Careful selection of such cases is necessary in order to prevent the problems outlined above.


Kimberly Poyner graduated from The University of Oklahoma with a B.A. in Journalism. She received her J.D. from Oklahoma City University School of Law in 2012. She passed the Wisconsin Bar Exam that same year, and is a member of the State Bar of Wisconsin and the Wisconsin Defense Counsel. She has been with the Ryan Law Firm since January 2015, and focuses primarily on insurance defense litigation.

Gabriel Houghton graduated from Marquette University Law School in 2012. After working as a solo practitioner for two years, he joined the Ryan Law Firm in 2014, and has focused on civil litigation with an emphasis on insurance defense.


1 Reference is made to the 2013-2014 Wisconsin Statutes unless otherwise indicated. Wisconsin Stat. § 804.01(2) (d)(1) reads:

Discovery of facts known and opinions held by experts, otherwise discoverable under par. (a) and acquired or developed in anticipation of litigation or for trial, may be obtained as follows: A party may through written interrogatories require any other party to identify each person whom the other party expects to call as an expert witness at trial. A party an expert whose opinions may be presented at trial. Upon motion, the court may order further discovery by other means, subject to such restrictions as to scope and such provisions, pursuant to subd. 3. concerning fees and expenses as the court considers appropriate.

2 See 1993-1994 Wisconsin Statutes.
3 Id.
4 Fed. R. Civ. P. 26(a)(2)(B) reads as follows:

Witnesses Who Provide a Written Report. Unless otherwise stipulated or ordered by the court, this disclosure must be accompanied by a written report—prepared and signed by the witness—if the witness is one retained or specially employed to provide expert testimony in the case or one whose duties as the party’s employee regularly involve giving expert testimony. The report must contain: i) a complete statement of all opinions the witness will express and the basis and reasons for them; ii) the facts or data considered by the witness informing them; iii) any exhibits that will be used to summarize or support them; iv) the witness’s qualifications, including a list of all publications authored in the previous ten years; v) a list of all other cases in which, during the previous four years, the witness testified as an expert at trial or by deposition; and vi) a statement of the compensation to be paid for the study and testimony in the case.

5 Prior reports, if they are similar, may suggest a lack of individual analysis of each case. Such reports may also be used to show inconsistencies in an expert’s opinions based on who hires him or her.
6 Wis. Stat. § 804.01(2)(a).
7 Konle v. Page , 205 Wis. 2d 389, 397-98, 556 N.W.2d 380 (Ct. App. 1996).
8 Id.
9 Wis. Stat. § 804.01(3)(a).
10 Wis. Stat. § 805.07(3).
11 See, e.g. , Cooper v. Schoffstall , 905 A.2d 482, 492 (Pa. 2006) (holding that a litigant must show cause and obtain an order before pursuing supplemental discovery of an expert’s financial information).
12 Primm v. Isaac , 127 S.W.3d 630, 634 (Ky. 2004).
13 See Cooper , 905 A.2d at 488 n.6.
14 Wis. Stat. § 804.01(2)(d)(1).
15 Wis. Stat. § 804.08(1)(a).
16 Wis. Stat. § 804.09(1) and (2).
17 Wis. Stat. § 804.09(3).
18 Wis. Stat. § 805.07(1) and (2)(a).
19 Id.
20 Wis. Stat. § 805.07(3).
21 See Wis. Stat. § 804.01(2)(d)(1), Wis. Sup. Ct. Order 95-03, Judicial Council Note, 191 Wis. 2d xix, xx (1995).
22 Wis. Stat. § 804.01(2)(d)(1).
23 Fed. R. Civ. P. 26(a)(2)(A) and (B).
24 Fed. R. Civ. P. 26(a)(2)(B)(i-vi).
25 Patricia Graczyk, The New Wisconsin Rules of Civil Procedure: Chapter 804 , 59 Marq. L. Rev. 475 (1976).
26 The Latin phrase is defined as follows: “a canon of construction holding that to express or include one thing implies the exclusion of the other, or of the alternative.” Black’s Law Dictionary , at 620 (8th Ed. 2004).
27 See, e.g. , Elkins v. Syken , 672 So.2d 517, 520 (Fla. 1996) (decision that medical experts need not produce 1099s was meant to forestall “any chilling effect on the availability of expert witnesses”) (emphasis added); Primm , 127 S.W.3d at 638-39 (concluding that “the information sought and the manner in which it has been requested is not only duplicative, but also so burdensome as to create a chilling effect on a litigant’s ability to find experts”) (emphasis added); Cooper , 905 A.2d at 494 (“[W]e are cognizant of the broader concern with a potential chilling effect.”) (emphasis added).
28 See State ex rel. Dudek v. Circuit Court, 34 Wis. 2d 559, 597, 150 N.W.2d 387 (1967) (discussing the importance of expert witnesses in modern litigation).
29 See Elkins, 672 So.2d at 520 (holding that medical experts need not produce 1099s absent “the most unusual or compelling circumstances”).
30 Cooper, 905 A.2d at 495 (quoting Syken v. Elkins, 644 So.2d 539, 545 (Fla. App. 1994)).
31 Current Procedural Terminology (CPT) is a medical code used to report medical, surgical, and diagnostic procedures and services to physicians and health insurance companies.
32 See Cooper, 905 A.2d at 496 (citing State ex rel. Creighton v. Jackson, 879 S.W.2d 639, 643 (Mo. Ct. App. 1994)).
33 See supra note 29.