Under the common interest doctrine, separately represented clients can avoid the normal waiver implications of sharing privileged communications by entering into a contractual arrangement. In Energy Policy Advocates v. Ellison, 980 N.W.2d 146 (Minn. 2022), the Minnesota Supreme Court officially recognized the common interest doctrine – but left one key question unanswered, and extended the doctrine where it isn't necessary.

The Minnesota Supreme Court found that the common interest doctrine protected non-public climate change-related "communications among attorneys in public law agencies." Id. at 150. Significantly, the court stated that "the common legal interest can be in a litigated or non-litigated matter . . . [b]ut a purely commercial, political, or policy interest is insufficient for the common-interest doctrine to apply." Id. at 153. Nearly every other court has required either litigation or anticipated litigation before recognizing an effective common interest agreement. It is unclear if the Minnesota Supreme Court adopted the minority view that would apply the common interest doctrine in transactional settings – without any anticipation of litigation. The court also announced that "[w]e hold that the common interest doctrine applies to attorney work product." Id. at 155. Under universal work product waiver principles, avoiding work product waiver does not require the exacting common interest doctrine standards.

The Minnesota Supreme Court's acknowledgment of the common interest doctrine is good news. An explicit expansion to purely transactional settings would have been much more significant, but it is not clear whether the court went that far.