It is a well-known maxim that the attorney-client privilege "extends only to communications and not to facts." Upjohn Co. v. United States, 449 U.S. 383, 395 (1981). It is similarly well established that while the identity of a client typically is not protected from disclosure, the privilege can be invoked to bar revealing a client's identity when doing so will necessarily disclose the substance of a privileged communication. See United States v. Liebman, 742 F.2d 807, 809 (3d Cir. 1984). These principles frame the conundrum presented when the Government seeks to compel lawyers to disclose their clients' identities.

Earlier this Term, the Supreme Court declined to review a decision by the U.S. Court of Appeals for the Fifth Circuit upholding a John Doe summons requiring a law firm to disclose the identities of clients to the IRS. Taylor Lohmeyer Law Firm v. United States, 957 F.3d 505 (5th Cir. 2020), cert. denied, 142 S. Ct. 87 (2021). This article addresses the Fifth Circuit's opinion, including the key features of three analogous cases the court analyzed in finding that the summons at issue did not breach the privilege. By declining to take up the issue, the Supreme Court has, for the moment, left it to the lower courts to establish the appropriate limits of John Doe summonses in this context, and Taylor Lohmeyer provides instructive guideposts to practitioners litigating application of the privilege to such circumstances.