When must ordinary case-in-chief expert testimony be disclosed?

Read the actual court-ordered times and sequence and any stipulation.

If neither supplies a schedule, identify the actual trial or trial-readiness date.

Establish whether the witness requires a prepared and signed report under Rule 26(a)(2)(B) or the subsection (C) summary.

1. Identify the actual actor, pleading and required act.
2. Establish the specified event and applicable order.
3. Resolve the material conditions. This guide publishes no calculated date.
4. Check final-day conditions and preserve service and filing evidence separately.

Establish the actual future event and applicable minimum lead time. Exclude the hearing or trial event and count backward under Rule 6(a). A final Saturday, Sunday or legal holiday moves backward to an earlier qualifying day. State-declared holidays under Rule 6(a)(6)(C) apply to forward periods only. Check federal and President or Congress declared holidays. Earlier service can satisfy a minimum lead time. This guide does not present the minimum as the only permissible action date.

Exclude the hearing or trial event and count backward under Rule 6(a). A final Saturday, Sunday or legal holiday moves backward to an earlier qualifying day. State-declared holidays under Rule 6(a)(6)(C) apply to forward periods only. Check federal and President or Congress declared holidays. Earlier service can satisfy a minimum lead time.

The text prioritizes court-ordered times and sequence and permits stipulation. Its default is a minimum lead time. This preset does not resolve the actual schedule or disclosure content.

Controlling disclosure schedule

Rule 26(a)(2)(D) first requires the court-ordered times and sequence. The ninety-day default applies absent a stipulation or court order.

Report or summary

Rule 26(a)(2)(B) identifies experts who ordinarily require a prepared and signed report with the listed contents. Subsection (C) specifies subject matter and facts-and-opinions summary for other experts.

Different rebuttal branch

Subsection (D)(ii) uses thirty days after the other party’s disclosure only for evidence intended solely to contradict or rebut the same subject matter.

• This page does not establish effective service, merits, compliance or an actual court grant.
• Service and filing are different acts. Verify both when required.

• Read the actual court-ordered times and sequence and any stipulation.
• Rule 26(a)(2)(D) first requires the court-ordered times and sequence. The ninety-day default applies absent a stipulation or court order.
• Rule 26(a)(2)(B) identifies experts who ordinarily require a prepared and signed report with the listed contents. Subsection (C) specifies subject matter and facts-and-opinions summary for other experts.
• Subsection (D)(ii) uses thirty days after the other party’s disclosure only for evidence intended solely to contradict or rebut the same subject matter.
• Rule 26(a)(4) ordinarily requires written, signed and served disclosures. Establish the actual required report or summary and complete effective service. For filing, Rule 6(a)(4) ordinarily uses midnight in the court’s time zone for electronic filing and scheduled clerk closing for other filing. A statute, local rule or order may set another time. These filing cutoffs do not establish effective service by every method. Preserve evidence of each actual required act.