Federal Rules of Evidence, official text as in effect December 1, 2024.
All 69 rules are searchable in TrialMate with no signal, which is what a courtroom usually leaves you. The amendment to Rule 801 takes effect in the app on December 1, 2026.
Unless the court orders otherwise, an expert may state an opinion—and give the reasons for it—without first testifying to the underlying facts or data. But the expert may be required to disclose those facts or data on cross-examination.
(As amended Mar. 2, 1987, eff. Oct. 1, 1987; Apr. 22, 1993, eff. Dec. 1, 1993; Apr. 26, 2011, eff. Dec. 1, 2011.)
Source: Federal Rules of Evidence, December 1, 2024, Administrative Office of the United States Courts, uscourts.gov.
This page reproduces the official text of the Federal Rules of Evidence for reference. It is not legal advice and adds no commentary. It does not replace the official publication, local rules, or the law that applies in your court. Check the current official text before relying on it.