Evidentiary Privileges: Attorney-Client Privilege and Rule 502
A privilege lets a person refuse to disclose certain confidential communications, even if they are relevant. This guide explains how evidentiary privileges work in federal court, the attorney-client privilege and inadvertent disclosure.
Where privilege law comes from
The common law — as interpreted by United States courts in the light of reason and experience — governs a claim of privilege unless any of the following provides otherwise: the United States Constitution; a federal statute; or rules prescribed by the Supreme Court. But in a civil case, state law governs privilege regarding a claim or defense for which state law supplies the rule of decision.
Recognized privileges include attorney-client, spousal, psychotherapist-patient and the Fifth Amendment privilege against self-incrimination.
Attorney-client privilege
The Supreme Court called it “the oldest of the privileges for confidential communications known to the common law” in Upjohn Co. v. United States, 449 U.S. 383, 389 (1981). It explained that the privilege protects “not only the giving of professional advice to those who can act on it but also the giving of information to the lawyer to enable him to give sound and informed advice.” Upjohn extended the privilege to communications between corporate employees and company lawyers. The privilege covers confidential communications for legal advice, not the underlying facts.
Inadvertent disclosure
Under Rule 502(b), an inadvertent disclosure in a federal proceeding “does not operate as a waiver” if the holder “took reasonable steps to prevent disclosure” and “promptly took reasonable steps to rectify the error.” Courts may also enter orders under Rule 502(d) protecting against waiver in a particular case.
Researching attorney-client privilege in your state
To research attorney-client privilege for a real matter, start with the primary sources. For example, read the statute, the rule and the documents in your own file. Then look for recent appellate decisions from your state, because they control how local courts read the law. After that, compare what you found with the federal rules that may also apply. Our state procedures guide and the Research Center can help you find and check each source.
Sources and further reading
Official sources used on this page:
Related reading on Lawtopolis:
Sources
- Fed. R. Evid. 501, 502
- Upjohn Co. v. United States, 449 U.S. 383 (1981)
Official sources:
law.cornell.edu/rules/fre/rule_501
law.cornell.edu/rules/fre/rule_502
static.case.law/us/449/html/0383-01.html
Sources last reviewed: 2026-10-23
Lawtopolis provides legal information and education, not legal advice. Using this site does not create an attorney-client relationship. Laws and court rules vary by jurisdiction and change over time; verify every authority against the official source and consult a licensed attorney in your jurisdiction about your situation.