When a lawyer steps into the role of mediator, the ethical ground shifts. The American Bar Association’s newest guidance—Formal Opinion 518 (Oct. 15, 2025)—makes that clear: don’t let anyone think you’re their lawyer. See ABA Formal Opinion 518 (Oct. 15, 2025).
Defining the Neutral Role
The opinion, issued by the ABA Standing Committee on Ethics and Professional Responsibility, revisits Model Rule 2.4, which governs lawyers serving as third-party neutrals. A mediator’s duty isn’t advocacy but clarity. The lawyer-mediator must ensure that all parties—particularly those without counsel—understand the difference between a mediator’s role and that of a lawyer representing a client.
As the Committee emphasizes, it’s not enough to simply say, “I’m not your lawyer.” Many participants are not “sophisticated consumers of mediation,” and the lawyer-mediator should take affirmative steps to explain what neutrality means in practice: no legal advice, no client-lawyer confidentiality, and no one whose “side” the mediator is on.
The opinion reminds mediators that this duty flows from the Model Rules’ core purpose—to prevent confusion about the lawyer’s role in any interaction. The mediator’s integrity depends on the parties’ confidence that no one is receiving hidden advocacy or advice.
Neutrality and Truthfulness
Formal Opinion 518 also explores the intersection of neutrality and Rule 8.4(c), which prohibits conduct involving dishonesty, fraud, deceit, or misrepresentation. Even though a mediator doesn’t represent any party, the duty of truthfulness still applies.
Here’s the key difference: a mediator doesn’t get the same leeway to “puff” as a negotiating lawyer does.
Lawyers advocating for clients can downplay weaknesses or exaggerate bargaining strength—within limits—because everyone understands it’s negotiation. But parties expect mediators to be neutral and truthful. When a neutral says “this is the best offer you’ll get,” or implies that a settlement is in a party’s best interest, that statement carries the weight of authority. The ABA warns that such assurances can be misleading and therefore unethical.
The Committee goes further, cautioning that mediators must not give credence to statements they know are false. Passing along unverified information is permissible if the mediator makes clear where it came from; endorsing it is not.
Conclusion
In practice, this opinion should prompt lawyers who serve as mediators to revisit their standard opening remarks, intake forms, and written disclosures. Explaining neutrality shouldn’t be a rote formality; it should be an intentional moment of orientation. Mediators should also take care when conferencing, summarizing offers, or providing “reality checks” about likely outcomes—moments where the line between legal information and legal advice can blur. When you’re the mediator, your words carry the weight of neutrality—and with it, a higher duty not to mislead.
