Sixth Circuit Says It Again: Outside Counsel’s Internal Investigations Are Privileged and Protected from Disclosure

In Summer 2025, the U.S. Court of Appeals for the Sixth Circuit issued a strongly worded decision in In Re: FirstEnergy Corporation (No. 24-3654)—confirming the core concept that internal investigations conducted by counsel and in anticipation of litigation are privileged and protected from disclosure.

When securities plaintiffs in the case sweepingly sought all documents “related to the internal investigation,” the district court incorrectly ordered their production. After much legal wrangling, the Sixth Circuit rebuked the district court on August 7, 2025, and reaffirmed in a per curiam opinion filed October 3, 2025. 

The Sixth Circuit got it right. The court restated what corporate America’s legal departments can and should rely upon: that internal investigations led by counsel are and will remain privileged. This opinion affirms the intent of the privilege—to allow companies to receive privileged legal advice and guidance in the setting of internal investigations, to uncover potential risk areas and take remedial action—without worrying that the investigation will become public at some later point.

The relevant background of this case is as follows. Following the federal indictment of the former speaker of the Ohio House of Representatives, Larry Householder, and related Department of Justice investigations into FirstEnergy, an Ohio public utilities company, shareholders brought a securities class action seeking documents regarding the company’s internal investigations. The district court ordered the company to produce the documents, and the company moved to stay pending resolution of its petition for a writ of mandamus. The Sixth Circuit granted the stay on August 7, 2025, concluding that the company was likely to succeed on its arguments since the lower court incorrectly applied the attorney-client privilege and work product doctrines—and that the company faced irreparable harm.

The Sixth Circuit relied on Upjohn v. United States, 449 U.S. 383 (1981), the seminal U.S. Supreme Court case that held that the attorney-client privilege applies when companies seek legal advice through internal investigations in response to civil and criminal investigations. The Sixth Circuit firmly held, “What matters for attorney-client privilege is not what a company does with its legal advice, but simply whether a company seeks legal advice.”

Addressing the attorney work product doctrine, the Sixth Circuit held that the documents generated by the internal investigation existed owing to the company’s “reasonable anticipation of litigation, as opposed to its ordinary business purposes,” meaning that the attorney work product doctrine also likely applied. The Sixth Circuit found a strong public interest in preserving both the attorney client privilege and the work product doctrine.

The October 3, 2025, per curiam opinion again granted the company’s motion for a stay and vacated the district court’s production order. The Sixth Circuit held that the district court rulings amounted to legal error that was sufficiently exceptional to warrant mandamus relief—again relying on Upjohn and the established principle that the work product doctrine applies to documents “prepared in anticipation of litigation,” Fed. R. Civ. P. 26(b)(3), meaning “because of” a “reasonable” anticipation as opposed to ordinary business purposes, In re Pros. Direct Ins. Co., 578 F.3d 432, 439 (6th Cir. 2009).

The decision affirms that companies can rightly expect that when they hire outside counsel to conduct sensitive internal investigations, the privileged advice and work product resulting from the investigation should and will remain protected from disclosure.

Epstein Becker Green Staff Attorney Ann W. Parks contributed to the preparation of this post.