Under the common interest doctrine, separately represented clients may sometimes contractually avoid the normal waiver impact of disclosing privileged communications to each other. But federal and state courts take widely varying approaches to this helpful (but dangerously imprecise) waiver-avoidance arrangement.

In Hankin v. Sewall, the court pointed to Maine Rule of Evidence 502(b)(3) as limiting the common interest doctrine’s application to a "pending action." No. BCD-REA-2023-00007, 2023 Me. Bus. & Consumer LEXIS 31, at *6 (Me. Bus. & Consumer Ct. July 3, 2023). Many courts are more generous, applying the doctrine if the common interest participants only anticipate litigation. The Maine court also warned that the common interest doctrine "does not extend … to communications shared amongst the parties themselves that do not either involve attorneys or disclose privileged communication." Id. at *7. That seems like an odd formulation. All courts seem to require privilege protection for the communications shared among the participants. Some courts also require a lawyer's participation, while others do not. Maine apparently takes the more restrictive approach on both the litigation and the lawyer participation issues.

Lawyers should never assume that a generic "common interest doctrine" protection will apply. There are wide variations among federal and states courts, and some formulations do not bring the certainty that the participants seek.