Code of Civil Procedure § 2034.415 – Production of Expert Materials Prior to Deposition
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Code of Civil Procedure § 2034.415 – Production of Expert Materials Prior to Deposition
PART 4. MISCELLANEOUS PROVISIONS [1855 – 2107]
( Heading of Part 4 amended by Stats. 1965, Ch. 299. )
TITLE 4. CIVIL DISCOVERY ACT [2016.010 – 2036.050]
( Title 4 added by Stats. 2004, Ch. 182, Sec. 23. )
CHAPTER 18. Simultaneous Exchange of Expert Witness Information [2034.010 – 2034.730]
( Chapter 18 added by Stats. 2004, Ch. 182, Sec. 23. )
( Article 3 added by Stats. 2004, Ch. 182, Sec. 23. )
Code of Civil Procedure § 2034.415
An expert described in subdivision (b) of Section 2034.210 whose deposition is noticed pursuant to Section 2025.220 shall, no later than three business days before his or her deposition, produce any materials or category of materials, including any electronically stored information, called for by the deposition notice.
(Added by Stats. 2016, Ch. 467, Sec. 3. (AB 2427) Effective January 1, 2017.)
CCP § 2034.415 Summary
This statute mandates that a retained expert witness—as described in subdivision (b) of Section 2034.210—whose deposition is noticed under Section 2025.220 must produce all materials or categories of materials, including electronically stored information (ESI), requested in the deposition notice no later than three business days before the deposition.
Purpose
The legal purpose of this rule is to increase the fairness and efficiency of expert witness depositions. Before CCP § 2034.415 was enacted (effective January 1, 2017), attorneys often complained of “trial by ambush” during expert depositions – it was common to show up at an expert’s deposition and be handed boxes of documents or a thumb drive full of the expert’s materials right as the questioning began. This left the deposing lawyer scrambling to read through voluminous data on the spot, undermining the ability to conduct an effective examination. The new law was a bipartisan effort by plaintiff and defense attorneys to solve this problem. By requiring that all materials an expert will rely on be produced a few days in advance, CCP § 2034.415 ensures the deposing party has time to review the expert’s file and prepare informed questions. This promotes a more organized and effective deposition process, reducing surprise and delay. Notably, the law did not expand what categories of information the expert must provide – it simply shifted the timing of production to before the deposition (including clarifying that electronically stored information (ESI) must be produced in usable form). In short, CCP § 2034.415’s purpose is to give fair notice of the expert’s opinions and bases, reflecting the broader goal of expert discovery: preventing unfair surprise at trial and allowing both sides to prepare fully.
Application
This rule applies when a party notices the deposition of a retained expert witness. The expert is required to:
Produce all materials specified in the deposition notice, including any ESI,
Ensure that these materials are delivered to the requesting party at least three business days prior to the scheduled deposition.
Failure to comply with this requirement may lead to motions to compel production, sanctions, or limitations on the expert’s testimony.
Illustrative Examples and Hypotheticals
To tie everything together, let’s walk through a couple of hypotheticals that illustrate CCP § 2034.415 in action:
Example 1: The Late Document Dump. Fact Pattern: Defense counsel schedules the deposition of Plaintiff’s retained economics expert, who will testify on lost earnings. The deposition notice requests “all materials considered by the expert,” etc. However, Plaintiff’s counsel only emails a copy of the expert’s resume and a one-page summary of conclusions, one day before the deposition. When the deposition begins, the expert brings a bankers box and hands defense counsel hundreds of pages of financial data, tax returns, and calculations that were not sent in advance. Result: Defense counsel is justifiably upset. Under CCP § 2034.415, those materials should have been produced three business days earlier. Here, they were not provided until the moment of the depo. Defense counsel could mark the deposition as “proceeding under protest” and perhaps conduct some preliminary questioning, but she will likely not finish the deposition. After the session, she files a motion to compel the production of all expert materials (though by now she has them, albeit at the last minute) and asks for sanctions. The court could order the expert to appear for a second deposition (at Plaintiff’s expense) so that defense counsel can question the expert after having had time to review the materials. The court would almost certainly order Plaintiff’s side to pay the costs of the first aborted deposition. If the judge suspects this was a tactic to ambush, they might go further and preclude the expert from testifying to anything not disclosed timely. This example underscores how failing to send materials ahead of time can lead to duplication of proceedings and monetary penalties, not to mention a tarnished reputation with the judge.
Example 2: Good Faith Compliance, No Prejudice. Fact Pattern: Plaintiff’s counsel designates an accident reconstruction expert. The expert doesn’t have a formal report, just a collection of notes and some computer simulations. Defense counsel notices the expert’s deposition and requests “all notes, simulations, and underlying data.” Plaintiff’s counsel, three days before the depo, provides the expert’s notes and notifies defense counsel that the simulation files (which are large) will be provided on a thumb drive at the deposition (perhaps due to technical transfer issues). At the deposition, defense counsel receives the thumb drive with the simulation data and takes a break to verify its contents. The expert is then deposed, and he explains the simulation results in detail. Defense counsel is able to question him effectively because she had the notes in advance and was generally aware of what the simulation involved. Result: Here, while ideally the electronic data would also have been delivered three days early, the slight delay caused no significant prejudice – the deposition wasn’t impeded, and defense counsel had enough information from the notes to formulate questions. It’s unlikely anyone would seek sanctions because Plaintiff’s counsel substantially complied with the rule. If defense counsel did complain to the court, the judge might simply tell Plaintiff’s counsel to be more careful, but since the deposition was successful, no harm no foul. This hypothetical shows that minor or technical violations that don’t harm the opposing party probably won’t lead to harsh sanctions. Judges focus on whether the opposing side got a “meaningful deposition” and fair opportunity to prepare.
Example 3: Intentional Withholding and Exclusion. Fact Pattern: Defense has a medical expert who examined the plaintiff and wrote a causation report. The defense team, hoping to reduce scrutiny, intentionally does not produce the doctor’s report during expert exchange or before the deposition. They plan to have the doctor present the report’s conclusions at trial without giving plaintiff’s counsel a preview. The deposition notice from plaintiff’s counsel asks for “all reports and writings,” but defense counsel provides nothing, claiming “the expert will explain everything at deposition.” At the deposition, the expert reveals there is a written report but states he was instructed not to share it; he reads portions of it aloud. Plaintiff’s counsel rightfully terminates the deposition and goes to court. Result: This is a textbook example of unreasonable failure to comply. The court would almost certainly exclude the defense expert’s testimony under CCP § 2034.300 for violating the disclosure requirements. The judge could find that the defense “intentionally manipulated the discovery process” by withholding the report. The likely sanction: the expert is not allowed to testify at trial at all, or at minimum, the expert cannot testify to opinions that were in the undisclosed report. This effectively hands a win to the plaintiff on that issue. Such a sanction is meant not only to penalize the offending party but also to deter others from similar discovery abuses.
These examples demonstrate the range of outcomes – from needing a redo of a deposition with cost sanctions, to no sanction for harmless issues, to full exclusion for egregious misconduct. The guiding principles are fairness and good faith. Parties who follow CCP § 2034.415 in good faith will keep their experts in play and have well-run depositions; those who flout it risk severe consequences.
Recent Updates and Case Law Interpreting CCP § 2034.415
As mentioned, CCP § 2034.415 itself was added relatively recently (effective 2017 via Assembly Bill 2427), and it hasn’t been amended since. The addition of this rule was part of a broader push to improve efficiency in civil cases. While the rule is straightforward, courts have been clarifying its application through case law in the years since:
Legislative Consensus: The legislative history confirms that AB 2427 was a consensus measure by both plaintiff and defense bar representatives, underscoring how non-controversial and practical this requirement was meant to be. Both sides recognized that depositions are more useful if experts’ materials are received ahead of time. This context can be helpful when arguing a motion – a judge will appreciate that the intent of the law is to facilitate a fair process, not to create traps.
Case Law – Emphasizing “Meaningful Deposition”: Courts have repeatedly echoed that the purpose of expert discovery (including CCP § 2034.415) is to enable a meaningful deposition and avoid surprise. In Staub v. Kiley (2014) 226 Cal.App.4th 1437, a case decided under prior law, the appellate court noted that excluding experts is a drastic step and should be reserved for when a party’s noncompliance undermines the opponent’s ability to prepare (in Staub, the plaintiff’s expert exclusion was reversed because the defense had not strictly followed the rules either and the plaintiff had offered to make the experts available for depo). Staub also cautioned that booting an expert can be tantamount to a terminating sanction if it wipes out someone’s case, so judges should carefully consider less severe options if possible.
Flores v. Superior Court (2024) – Discussed Above: This recent appellate decision is likely to be cited often in disputes about expert discovery sanctions. It provides a measured framework: look at whether the violation was intentional or tactical, whether the opposing side still got what they needed (eventually), and what the impact on the trial would be if the expert were excluded. Flores essentially reminds trial courts to use a proportional response. After Flores, attorneys facing a late production might argue: “According to Flores, exclusion is not appropriate unless my ability to depose the expert was truly thwarted or the conduct was egregious.” Conversely, the party seeking sanctions will argue that, unlike Flores, their situation does involve prejudice or bad faith, so exclusion is warranted. Each case is fact-specific, but Flores sets a tone of caution against overkill sanctions.
No New Statutory Changes as of 2025: There haven’t been further amendments to CCP § 2034.415 or related expert disclosure statutes since the 2016/2017 changes. However, attorneys should keep an eye on any developing case law, since appellate decisions flesh out scenarios not explicitly described in the statute (like what exactly counts as “materials … called for,” or how to handle partial compliance). Also, be aware of local rules or judge-specific guidelines: Some judges issue pretrial orders reinforcing the three-day rule or requiring counsel to exchange expert deposition exhibits in advance. Always read the local department rules.
Federal vs. State Difference: It’s worth noting for context (especially for law students) that California’s approach here differs from federal court. In federal practice, experts must produce their reports with their Rule 26 disclosures, and there is no specific rule requiring production of expert file materials 3 days before depo – but typically, by custom or court order, attorneys arrange to get documents beforehand. California codified this courtesy into a mandate with CCP § 2034.415. So California state practitioners need to remember this extra timing requirement, as it’s unique to state court practice.
Overall, the trend in case law is to enforce CCP § 2034.415 firmly but fairly – encouraging full compliance, and using sanctions when a party’s failure genuinely jeopardizes the opposing side’s trial preparation. The best “recent update” one can glean is that courts are balancing enforcement with proportionality. The rule is here to stay, and savvy litigators are building it into their standard operating procedures for expert discovery.
