Mechanism 05
Mandatory exclusion of a late-designated expert
Is exclusion of a late-designated expert mandatory or discretionary in Texas state court?
Mandatory. Under Tex. R. Civ. P. 193.6, a party who fails to timely designate an expert may not offer that testimony unless the court finds good cause or a lack of unfair surprise or prejudice — and the burden of that showing is on the party who missed the deadline. In Murphy v. Liberty Hill Construction, the plaintiffs' construction expert, designated after discovery closed and a week before the summary judgment hearing, was struck in its entirety.
By John P. Henry · Tex. R. Civ. P. 193.6 · Reviewed 2026-08-02
The authority
A party who fails to make, amend, or supplement a discovery response in a timely manner may not introduce in evidence the material or information that was not timely disclosed … unless the court finds that there was good cause, or the failure … will not unfairly surprise or unfairly prejudice the other parties.Tex. R. Civ. P. 193.6
Tex. R. Civ. P. 193.6
When it applies
Any untimely designation, supplementation or disclosure — expert or fact witness. It is at its most powerful where the excluded testimony is the only proof of an element, because exclusion then converts directly into a no-evidence summary judgment.
How it is proved up
- Fix the deadline on the record: the discovery control plan level, the scheduling order, and the computation under Rule 195.2 from the trial setting.
- Establish the designation date from the certificate of service, not from when it arrived.
- Put the burden where the rule puts it. Do not argue prejudice first — say that the rule excludes, and that the burden of the exception is theirs.
- Move to strike in a separate instrument and obtain a separate order, so exclusion survives independent of the summary judgment ruling.
- Then file the no-evidence motion on the element the excluded expert was the only support for.
What defeats it
- A good-cause showing, or a genuine absence of surprise — for example where the expert had already been deposed or identified in another form.
- A continuance, which can cure the prejudice and is the response a well-advised opponent asks for.
- Waiver by the movant: taking the expert's deposition without objection undercuts the surprise argument.
Where I have used it
Murphy — the plaintiffs' construction expert, designated a week before the summary judgment hearing and after discovery had closed, struck in its entirety.
The order
Exhibit — as signed
Order Granting Final Summary Judgment · March 4, 2026 — evidence struck, all eight causes dismissed with prejudice
CAUSE NO. 25-0131-C26 GREGG MURPHY and DAYLA MURPHY, Plaintiffs v. LIBERTY HILL CONSTRUCTION, LLC and THOMAS MCGRATH, Defendants IN THE DISTRICT COURT OF WILLIAMSON COUNTY, TEXAS 26th JUDICIAL DISTRICT ORDER GRANTING FINAL SUMMARY JUDGMENT On January 21, 2026, the Court heard Plaintiffs' motion to compel arbitration. The Court considered the Plaintiffs' motion and the attached declaration of Gregg Murphy in support. The Court also considered Liberty Hill Construction's ("LHC") response and the attached declaration of Thomas McGrath in support. The Court finds that Plaintiffs substantially invoked the judicial process to LHC's detriment and prejudice and have waived their right to arbitration. The Plaintiffs' motion to compel arbitration is DENIED. The Court also heard LHC's Objections to Plaintiffs' Summary Judgment Evidence. The Court SUSTAINS the objections and STRIKES all documents attached to the Gregg Murphy and Johnny Ramirez Declarations as unauthenticated hearsay. The Court also SUSTAINS the Defendants' objections to the Gregg Murphy Declaration. Gregg Murphy, as a homeowner, cannot provide competent summary judgment evidence concerning the alleged deficiencies in LHC's work and did not provide any foundation for the opinions. The Court also SUSTAINS Defendants' objection to the admission of the Johnny Ramirez Declaration in its entirety where it was untimely under the mandatory exclusion requirement of […] [Page 1 ends. Transcript continues on the following page of the order.]
Transcribed verbatim from the file-stamped copy. Public record. Reproduced because a result a reader can verify is worth more than a result described.
Questions
Who has the burden to show good cause under Rule 193.6?
The party who failed to timely designate. The rule is written as an exclusion with narrow exceptions, and the burden of establishing an exception rests on the party seeking to escape it.
Can a late-designated expert be cured by a continuance?
Sometimes. A continuance can eliminate unfair surprise and prejudice, and courts have discretion to grant one. That is why the motion to strike should be set and heard on a schedule that makes a continuance costly to the other side.
What happens if the excluded expert was the only evidence on an element?
The exclusion becomes dispositive. The usual sequence is to obtain the order striking the testimony and then move for no-evidence summary judgment under Rule 166a(i) on the element the testimony was offered to prove.