Expert Witnesses in Maryland
According to Maryland Rule 5-702, an expert witness is someone whose opinions go beyond common knowledge and are based on specialized expertise. The witness does not have to hold a specific license or degree unless the subject matter of the case requires it (for example, certain medical malpractice contexts). What matters is whether the witness is sufficiently qualified in the relevant field and whether the testimony is reliable and relevant.
Rules Governing Disclosure
When a party expects an expert witness to testify at trial, Maryland Rule 2-402 permits the opposing party to obtain discovery concerning that expert. The purpose of this discovery is to ensure fairness by allowing the opposing party to understand the expert’s anticipated testimony and to prepare an effective response or cross-examination before trial.
Expert Qualifications: A detailed summary of the expert’s credentials must be provided, including education, training, and professional experience, to establish the expert’s competence and credibility.
Opinions and Bases for Opinions: The expert must clearly state their opinions and explain the factual and methodological bases for each opinion, enabling the opposing party to meaningfully prepare for examination and cross-examination.
Data Considered: The disclosure must identify all data, facts, or information reviewed or relied upon by the expert in forming their opinions, allowing the opinions to be evaluated and tested independently.
Fee Structures: The terms of the expert’s compensation, including fee structures, must be disclosed, as they may bear on potential bias or credibility.
Prior Testimony: The expert must provide a list of other cases in which they have testified as an expert, whether at trial or by deposition, within the preceding four years.
In Maryland, failure to properly disclose an expert under Rule 2-433 places the expert testimony at substantial risk of exclusion and exposes the offending party to additional sanctions, including monetary penalties, to deter non-compliance. Compliance with Rule 2-402(g) and scheduling orders is therefore critical, as courts prioritize fairness and trial readiness over leniency for incomplete or late expert disclosures.
Admissibility Standards
Maryland now follows a Daubert-style admissibility regime grounded in Maryland Rule 5-702 and shaped by case law, most importantly Rochkind V. Stevenson, 471 Md. 1 (2020), which clarified how expert evidence must be evaluated by trial courts before it can be admitted.
Maryland’s post-Rochkind approach incorporates Daubert principles within the structure of Rule 5-702, emphasizing judicial discretion, context-specific reliability analysis, and avoidance of rigid or formulaic admissibility rules.
The court held that Maryland Rule 5-702 provides the governing standard for the admissibility of expert testimony, requiring trial courts to evaluate expert evidence based on the following criteria:
1. Whether the expert is qualified
2. Whether the testimony will help the trier of fact understand the evidence
3. Whether the testimony is based on sufficient facts or data
4. Whether the testimony is the product of reliable principles and methods
5. Whether the expert has reliably applied those methods to the facts of the case
Attorney–Expert Communication Protection
Maryland provides explicit protection for most communications between attorneys and expert witnesses as part of its expert-discovery framework under Maryland Rule 2-402(g). These protections are designed to preserve attorney work product and trial strategy while still allowing fair disclosure of the substance of expert opinions that will be presented at trial.
As a general rule, communications between an attorney and a testifying expert are protected from discovery, including:
emails, memoranda, and correspondence between counsel and the expert;
attorney comments, edits, or suggestions on draft reports;
discussions of litigation strategy, legal theories, or case framing; and
internal communications reflecting counsel’s mental impressions or trial preparation.
These materials are treated as work product and are not discoverable merely because they were shared with an expert.
Maryland Rule 2-402(g) carves out narrow, mandatory exceptions to this protection. Communications are discoverable only to the extent they relate to:
Compensation – the terms and conditions of the expert’s payment;
Facts or data provided by counsel that the expert considered in forming opinions; and
Assumptions supplied by counsel and relied upon by the expert.
The disclosure obligation is substance-focused, not communication-focused. In practice, this usually means identifying the facts, data, or assumptions relied upon—not producing the attorney-expert correspondence itself unless necessary.
Compensation
In Maryland, expert witnesses are compensated according to private agreement, subject to court oversight for reasonableness when discovery is sought. There is no statutory fee schedule or cap unique to experts; compensation is governed primarily by the Maryland Rules of Civil Procedure and case law.
Unless the court orders otherwise on the ground of manifest injustice, the party seeking the expert’s deposition is required to pay the expert a reasonable fee. This obligation includes compensation for the time the expert spends attending the deposition, as well as for reasonable travel time and travel-related expenses incurred in going to and from the deposition. The rule further provides that the rate paid for deposition attendance may not exceed the rate the expert charges for time spent preparing for a deposition, thereby preventing inflated or inconsistent billing practices and ensuring proportionality in expert compensation.
In addition to attendance and travel, subsection (g)(3)(A) also requires payment for time spent preparing for the deposition, recognizing that meaningful deposition testimony often requires advance review of materials, reports, and analyses. Subsection (g)(3)(B) reinforces this principle in cases involving experts whose opinions were acquired or developed in anticipation of litigation or for trial, as addressed in subsection (g)(2). In those circumstances, the discovering party must pay a reasonable fee for the expert’s deposition preparation, acknowledging that litigation-retained experts typically require more extensive preparation due to the nature and complexity of their work.
Limits on Number of Expert Witnesses
Maryland does not impose a fixed numerical limit on the number of expert witnesses a party may present in a civil case. There is no rule or statute that caps experts by category or per side.
That said, the absence of a numeric cap does not mean unlimited expert testimony is permitted.
Maryland trial courts have broad discretion to control expert evidence under the Maryland Rules of Civil Procedure and the Rules of Evidence. Courts may limit the number of experts to prevent testimony that is cumulative, duplicative, or unnecessary, particularly where multiple experts are offered on the same subject matter. This authority flows from the court’s general power to manage trials efficiently and from evidentiary principles requiring that testimony assist the trier of fact rather than overwhelm or confuse it.
Out-of-State Expert Qualification
Maryland does not impose a residency or in-state licensure requirement for expert witnesses. An expert may be from any state (or country) so long as the witness satisfies Maryland’s qualification and admissibility standards. The focus is on expertise and reliability, not geography.
State-Specific Statutes & Local Rules
Md. Rule 2-402(g): Governs expert discovery and disclosures
Rule 5-702, Md. Rules of Evidence: Controls expert witness admissibility
Rule 2-433: Sanctions for failing to properly disclose an expert
