Expert Witnesses in Texas
Under Rule 702 of the Texas Rules of Evidence, an expert witness is a person who is qualified by knowledge, skill, experience, training, or education and whose scientific, technical, or other specialized knowledge will help the trier of fact understand the evidence or determine a fact in issue. The rule permits such a witness to testify in the form of an opinion or otherwise, provided that threshold of helpfulness to the factfinder is met.
Rules Governing Disclosure
Under the Texas Rules of Civil Procedure (effective March 1, 2026), testifying expert disclosures are automatic in non-Family-Code suits. A party must disclose each expert's name, address, phone number, subject matter of testimony, and the general substance of their opinions with a brief basis summary. For retained or controlled experts, the party must also produce all documents provided to or prepared for the expert, the expert's resume, publications from the past ten years, and a four-year testimony history. Beyond disclosure, expert discovery is limited to oral depositions and court-ordered reports.
In Family Code suits, governed by Rules 194a and 195a, expert disclosures are not automatic. The required disclosures under Rule 194a.2(f) cover the expert's name, address, and phone number, subject matter of testimony, the general substance of opinions and their basis, and for retained experts, all documents and materials plus the expert's resume and biography. However, Family Code disclosures are narrower than their non-Family-Code counterparts — they do not require the ten-year publications list, the four-year testimony history, or the compensation statement. If the expert's factual observations or opinions have not been reduced to tangible form, the court may order the expert to do so under Rule 195a.5. The party's duty to amend and supplement these disclosures is governed by Rule 193.5, and for retained experts, supplementation of deposition testimony or written reports is required but only regarding the expert's mental impressions, opinions, and their basis.
Admissibility Standards
Texas follows what is commonly known as the Robinson standard for expert testimony admissibility, which is the state's version of the federal Daubert framework.
Rule 702 of the Texas Rules of Evidence provides the statutory foundation. It allows a witness qualified by knowledge, skill, experience, training, or education to testify in the form of an opinion if their specialized knowledge will help the trier of fact understand the evidence or determine a fact in issue. On its face, the rule sets two baseline requirements — the expert must be qualified, and the testimony must be helpful. But Texas case law has built a more demanding gatekeeping framework on top of this text.
The Texas Supreme Court adopted the Daubert standard in E.I. du Pont de Nemours & Co. v. Robinson (1995), holding that the proponent of expert testimony must show the testimony is relevant to the issues in the case and based upon a reliable foundation. The trial judge serves as a mandatory gatekeeper, determining before the testimony reaches the jury whether it meets both prongs. The court outlined non-exclusive reliability factors that echo the federal Daubert criteria, including whether the theory or technique can be and has been tested, whether it has been subjected to peer review and publication, the known or potential rate of error, the existence and maintenance of standards controlling the technique's operation, and the degree to which the theory or technique is generally accepted in the relevant scientific community
Attorney–Expert Communication Protection
Attorney-expert communications are broadly protected from discovery regardless of form, except for three narrow categories: communications about the expert's compensation, communications identifying facts or data the attorney provided that the expert considered in forming opinions, and communications identifying assumptions the attorney provided that the expert relied on. Draft expert reports and draft disclosures are also fully protected from discovery, regardless of the format in which they are recorded.
Compensation
The Texas Rules of Civil Procedure address expert compensation in two ways. On the disclosure side, a party must reveal the compensation being paid to a retained testifying expert for study and testimony in the case. This ensures the opposing side can assess potential bias. On the cost allocation side, when a party deposes an expert retained by the opposing side, the retaining party — not the deposing party — bears all reasonable fees the expert charges for preparation, testimony, review, and correction time.
Compensation also falls outside the attorney-expert communication privilege. Any communications between the attorney and the expert relating to payment arrangements remain fully discoverable.
Limits on Number of Expert Witnesses
The Texas Rules of Civil Procedure do not impose a hard cap on the number of testifying experts a party may designate. However, two provisions create indirect constraints.
Under Rule 167.4 (Offer of Settlement; Award of Litigation Costs), when litigation costs are awarded following an unsuccessful settlement offer, recoverable expert witness fees are limited to reasonable fees for no more than two testifying experts. A party can designate more than two, but only the fees for two are recoverable as litigation costs under this rule.
Under Rule 190.3 (Level 2 Discovery Control Plan), each side is allotted 50 hours of total oral deposition time for examining opposing parties, their designated experts, and persons under their control. If one side designates more than two experts, the opposing side receives an additional six hours of deposition time for each expert beyond the second. This creates a practical disincentive — designating additional experts automatically gives the other side more deposition time, increasing both exposure and cost.
So while there is no outright numerical limit, these two provisions work together to discourage parties from designating experts beyond a practical baseline of two, by tying financial and procedural consequences to each additional designation.
Out-of-State Expert Qualification
In general civil litigation, there is no bar on out-of-state experts — qualification turns entirely on the expert's knowledge and the reliability and relevance of their testimony under the Rule 702 gatekeeping framework. In medical malpractice cases, however, out-of-state medical experts face additional regulatory and qualification requirements, including oversight by the Texas Medical Board and stricter standards around field-specific practice and teaching experience.
