Rebuttal experts address the same subject matter as an opposing expert's disclosure, contradicting or limiting those opinions. Federal practice permits rebuttal disclosure within thirty days of the opposing disclosure absent a different schedule.

Rebuttal must respond rather than raise new affirmative theories.

Alternative Names:

Rebuttal Witness (Expert), Responsive Expert

Why it Matters?

The scope limitation is enforced, and rebuttal reports advancing affirmative opinions on issues the opposing expert did not address are struck as untimely affirmative disclosures. That matters for a defendant that failed to designate on an issue and attempts to cure through rebuttal. Framing every rebuttal opinion as responsive to specific opposing opinions, with citations, protects against the challenge.

Frequently asked questions

What may a rebuttal expert address?

What may a rebuttal expert address?

The same subject matter as the opposing expert's disclosure. New affirmative theories are struck as untimely affirmative disclosures.

How is the scope challenge avoided?

How is the scope challenge avoided?

By framing each rebuttal opinion as responsive to a specific opposing opinion, with citations to the report being answered.