Louisiana Expert Witness Rules: What Litigators Need to Know

Louisiana applies a civil law framework infused with federal-style discovery practices to the handling of expert witnesses. Expert disclosure is governed by the Louisiana Code of Civil Procedure (La. C.C.P.) and Louisiana Code of Evidence, with specific rules requiring both pretrial identification and admissibility vetting. Expert testimony is crucial in complex litigation, including personal injury, medical malpractice, and toxic torts, and parties must be vigilant in adhering to procedural timelines, discovery obligations, and evidentiary standards to ensure expert opinions reach the jury.

Designation Requirements

Louisiana requires expert identification during discovery, rather than through a formal motion. Under La. C.C.P. art. 1425, a party may be compelled through interrogatories to identify:

• The name and address of any expert expected to testify at trial
• The subject matter of the expert’s testimony
• The substance of facts and opinions to which the expert is expected to testify
• A summary of the grounds for each opinion

This rule applies broadly to both retained and non-retained experts. The timing of such disclosures is usually controlled by pretrial scheduling orders, which may establish staggered deadlines for initial and rebuttal experts. Failure to comply with these disclosure obligations can result in preclusion of the expert under La. C.C.P. art. 1471, the state’s sanctions provision for discovery violations.

Expert Disclosure Process

Louisiana law permits detailed expert discovery but does not require expert reports unless ordered by the court. Under La. C.C.P. art. 1425(D):

• A party may obtain discovery of facts known and opinions held by an expert expected to testify at trial
• Discovery may proceed by deposition, interrogatories, or requests for production

Unless a report is voluntarily provided or required by a case-specific order, expert disclosures typically consist of:

• A summary of the expert’s expected testimony
• A description of the underlying data and methodology
• The expert’s qualifications and prior testimony
• Compensation information for the expert’s work

In many complex civil cases, Louisiana courts encourage or require parties to produce written reports to clarify opinions and avoid trial-by-ambush. Additionally, in medical malpractice litigation, expert disclosures are shaped by the Medical Review Panel process governed by La. R.S. § 40:1231.8.

Required Declarations

While expert declarations are not required for initial disclosures, they are often essential during summary judgment proceedings. Under La. C.C.P. art. 967, affidavits used to support or oppose a motion for summary judgment must:

• Be made on personal knowledge
• Set forth admissible facts
• Demonstrate the affiant’s competence to testify

If a party’s claim or defense relies on expert opinion, it must submit a sworn affidavit or declaration to withstand summary judgment. This requirement is strictly enforced in medical malpractice, products liability, and engineering negligence cases.

Additionally, plaintiffs in medical malpractice actions must submit their claim to a Medical Review Panel before filing suit. The panel’s decision, while not binding, is often supplemented with expert declarations to establish breach of duty and causation.

Fees and Compensation

Louisiana does not regulate expert fees by statute. Compensation is typically established through private agreement between the expert and the retaining party. However, La. C.C.P. art. 1425(C) provides that when one party seeks to depose the other’s expert, the deposing party must pay a reasonable fee for:

• Time spent preparing for and attending the deposition
• Any additional services rendered in discovery

If the fee is contested, the court may determine whether the amount is reasonable based on the expert’s experience, market rates, and the complexity of the issues.

Discovery Scope and Limitations

Discovery of expert testimony in Louisiana is governed by La. C.C.P. art. 1425, which provides for:

• Full disclosure of testifying experts’ identities, opinions, and supporting materials
• Access to any underlying data, publications, or tests used to form the opinion
• Discovery of the expert’s compensation arrangement

However, discovery of non-testifying or consulting experts is sharply limited. These experts are shielded from discovery absent exceptional circumstances, such as when the expert’s findings cannot be obtained elsewhere.

Louisiana courts do not formally shield draft reports or communications between counsel and expert witnesses. These materials may be discoverable unless explicitly protected under the work-product doctrine or a protective order.

Admissibility Standards

Louisiana follows a Daubert-style standard for the admissibility of expert testimony. Under La. Code Evid. art. 702, expert opinions are admissible if:

1. The witness is qualified by knowledge, skill, experience, training, or education
2. The testimony will assist the trier of fact in understanding the evidence
3. The testimony is based on sufficient facts or data
4. The opinion is the product of reliable principles and methods
5. The expert has reliably applied those methods to the facts of the case

This standard was affirmed in State v. Foret, 628 So. 2d 1116 (La. 1993) and later codified in Article 702. Louisiana trial courts act as gatekeepers, particularly in scientific, engineering, or financial testimony. Courts may hold pretrial hearings to assess reliability, and parties often challenge admissibility via motions in limine.

Key Deadlines & Strategy Notes

There is no statewide uniform deadline for expert disclosures in Louisiana. Instead, courts issue case-specific scheduling orders that typically include:

• Initial expert disclosure: Often 90–120 days before trial
• Rebuttal expert disclosure: 30–60 days after initial disclosures
• Expert depositions: Deadline set by pretrial order, typically before discovery closes
• Daubert motions/motions in limine: Filed in advance of trial, often 30–45 days prior
• Medical Review Panel expert participation: Must be completed before filing suit under La. R.S. § 40:1231.8

Strategically, early expert retention is critical, particularly in malpractice, construction, and toxic exposure cases. Louisiana’s adoption of a strict Daubert standard means that experts must not only be credentialed but must also apply accepted methodologies with precision.

State-Specific Statutes & Local Rules

• La. C.C.P. art. 1425: Governs expert discovery and depositions
• La. C.C.P. art. 967: Requirements for expert affidavits at summary judgment
• La. Code Evid. art. 702: Daubert-based admissibility standard
• La. R.S. § 40:1231.8: Medical Review Panel procedures and deadlines
• State v. Foret, 628 So. 2d 1116 (La. 1993): Louisiana’s adoption of Daubert criteria

Local rules in Orleans Parish, East Baton Rouge, and Jefferson Parish may supplement these standards with customized discovery schedules or expert disclosure forms. Practitioners should consult individual case management orders and judge-specific protocols.