Idaho Rules of Civil Procedure Rule 26(e). Supplementation of Responses.
A party who has responded to a request for discovery with a response that was complete when made is under no duty to supplement the response to include information thereafter acquired, except as follows:
(1) A party is under a duty seasonably to supplement the response with respect to any question directly addressed to (A) the identity and location of persons having knowledge of discoverable matters, and (B) the identity of each person expected to be called as an expert witness at trial, the subject matter on which the person is expected to testify, and the substance of the person's testimony.
(2) A party is under a duty seasonably to amend a prior response if the party obtains information upon the basis of which (A) the party knows that the response was incorrect when made, or (B) the party 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.
(4) If a party fails to seasonably supplement the responses as required in this Rule 26(e), the trial court may exclude the testimony of witnesses or the admission of evidence not disclosed by a required supplementation of the responses of the party.
(Amended March 30, 1988, effective July 1, 1988.)