A party who has responded to a request for discovery with a response that was complete when made is under no duty to supplement his response to include information thereafter acquired, except as follows:
Art. 1428.Supplementation of Responses
Book II. Ordinary Proceedings · Title III. Production of Evidence · Chapter 3. Discovery · Enacted 1976 · no amendments on record · Last verified July 30, 2026
In one sentenceArticle 1428 provides that a party generally has no duty to update a discovery response that was complete when made, except to keep witness- and expert-identification answers current, correct a response later known to be wrong or no longer true, or comply with a court order, agreement, or new request for supplementation.
Full Text of Art. 1428
(1) A party is under a duty seasonably to supplement his response with respect to any question directly addressed to the identity and location of persons having knowledge of discoverable matters, and the identity of each person expected to be called as an expert witness at trial, the subject matter on which he is expected to testify, and the substance of his testimony.
(2) A party is under a duty seasonably to amend a prior response if he obtains information upon the basis of which he knows that the response was incorrect when made, or he knows that the response though correct when made is no longer true and the circumstances are such that a failure to amend the response is in substance a knowing concealment.
(3) A duty to supplement responses may be imposed by order of the court, agreement of the parties, or at any time prior to trial through new requests for supplementation of prior responses.
Amendment History
Acts 1976, No. 574, §1.
Plain-English Summary
Once a discovery response is complete, Article 1428 doesn't automatically put a party on the hook to keep updating it as facts develop. That baseline matters because it tells both sides exactly when a party is required to circle back, rather than leaving supplementation as an open-ended, ongoing obligation.
Two situations always require an update. A party has to seasonably supplement any response touching who has knowledge of discoverable matters, and who's expected to testify as an expert, on what subject, and to what effect. And a party has to seasonably amend a response once they learn it was incorrect when given, or that it has since become untrue, if staying silent would amount to a knowing concealment.
Beyond those two triggers, a duty to supplement can also be imposed directly -- by court order, by agreement between the parties, or through a new request for supplementation filed any time before trial.
Frequently Asked Questions
Do I have to update my discovery answers if new facts come up later?
Generally not, unless one of Article 1428's exceptions applies: keeping witness- and expert-identification answers current, correcting a response known to be wrong or no longer true, or complying with an order, agreement, or new request.
What if I learn my earlier discovery answer was wrong?
Article 1428(2) requires a seasonable amendment if failing to correct it would amount to knowing concealment.
Can a court order me to supplement my discovery responses?
Yes. Paragraph 3 lets a duty to supplement arise from a court order, an agreement between the parties, or a new request filed any time before trial.
Do I have to keep my expert witness disclosures current?
Yes. Paragraph 1 requires seasonable supplementation of the identity of expected expert witnesses, their subject matter, and the substance of their testimony.
Source & verification. Article text is reproduced verbatim from
the Louisiana Code of Civil Procedure (legis.la.gov). Enacted by the Louisiana Legislature.
Last verified July 30, 2026.
· Official source
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