A caucus in mediation is a private meeting between the mediator and one side of a dispute, held away from the other party so you can speak candidly about your concerns, priorities, and flexibility without the other side listening. The mediator then moves between rooms, carrying only the information each side authorizes, to push the parties toward resolution. It is one of the most commonly used tools in mediation, and it is often what separates a session that settles from one that stalls.
How a Caucus Unfolds in a Session
Most mediations open with a joint session. Everyone sits together, each side presents their perspective, and the mediator sets ground rules. At some point, the mediator separates the parties into different rooms for private conversations. Sometimes that happens within minutes of opening remarks. Other times, the joint session runs for an hour or more before anyone splits up. There is no fixed rule.
Once the parties are in separate rooms, the mediator meets with one side, has a focused conversation, then walks to the other room and does the same. The back-and-forth can repeat many times. In complex commercial disputes, parties often spend the vast majority of their time apart, with the mediator moving between them for hours. Practitioners sometimes call this shuttle diplomacy.
In straightforward cases, a single caucus might last 15 to 30 minutes. In high-stakes litigation, a caucus round can stretch past an hour, especially when the mediator is walking through detailed risk analysis. Full-day civil mediations commonly run four to eight hours, and caucuses consume most of that time.
When a Mediator Calls a Caucus
Experienced mediators do not caucus randomly. They watch for signals that a private conversation will be more productive than continued joint discussion. The common triggers:
- Emotional escalation. When anger starts feeding on itself across the table, a caucus lets each side vent without provoking the other.
- Impasse. When direct negotiations stall and the parties keep repeating positions, a private conversation lets the mediator explore hidden flexibility neither side wants to show publicly.
- Unrealistic expectations. When one party’s view of their case is far out of step with reality, the mediator can challenge that view privately without embarrassing anyone.
- Power imbalance or inexperience. If one side is less experienced with negotiation, a caucus gives the mediator space to help that party think through strategy and weigh offers.
- Confidential information. When a party needs to share something sensitive, such as financial constraints or a settlement authority limit, that the other side should not see.
- Personal attacks. When joint session has devolved into finger-pointing rather than problem-solving, separating the parties resets the dynamic.
Some mediators announce at the start that they plan to use caucuses. Others wait and see how the joint session unfolds. You can also ask for a caucus yourself if you feel one would help.
What the Mediator Does in the Private Room
The mediator’s role in a caucus is more active than most people expect. They are not just listening politely and carrying messages.
They ask probing questions to understand what you actually need, as opposed to what you have been demanding. There is almost always a gap between a stated position (“I want $500,000”) and the underlying interest (“I need enough to cover my medical bills and feel like the other side took this seriously”). The caucus is where that gap gets explored.
They reality-test your case. This is where a mediator might point out weaknesses in your legal position, question the likelihood of a favorable trial outcome, or push back on assumptions. They are not being adversarial. They are helping you see the case the way a judge or jury might. Mediators often ask you to think through both the best and worst realistic outcomes if you walk away from the table and take your chances in court.
They help generate options. Once the mediator understands both sides’ real interests, gathered from separate caucuses, they can suggest solutions neither party would have proposed in a joint session. A mediator who has been in both rooms often sees overlap the parties themselves cannot.
With your explicit permission, they carry proposals and responses between rooms. They may soften the delivery, reframe demands as interests, or present an offer in a way that is more likely to get traction with the other side. This translation function is where experienced mediators earn their fees.
What the Mediator Can and Cannot Repeat
Confidentiality is the single feature that makes caucuses work. If you could not trust that the mediator would keep your private disclosures private, you would never reveal your true bottom line, and the exercise would collapse.
The Model Standards of Conduct for Mediators, jointly adopted by the American Bar Association, the American Arbitration Association, and the Association for Conflict Resolution, addresses this directly. Standard V provides that a mediator who meets with anyone in a private session “shall not convey directly or indirectly to any other person, any information that was obtained during that private session without the consent of the disclosing person.”1American Arbitration Association. Model Standards of Conduct for Mediators That is a flat prohibition with one exception: your permission.
In practice, at the end of a caucus the mediator will typically ask something like, “What from our conversation can I share with the other side?” You control the answer. You might authorize the mediator to convey a specific dollar figure but not the reasoning behind it. You might let them share your interest in a non-monetary term but keep your overall settlement authority confidential. The mediator is ethically bound to respect those boundaries.
The same Model Standards also protect self-determination, requiring that the mediator run the process in a way that lets each party make “free and informed choices as to process and outcome.”2Association for Conflict Resolution. Model Standards of Conduct for Mediators A mediator who leaked caucus information without consent would violate both standards at once.
Legal Protection for What You Say
Beyond the mediator’s ethical duty, legal rules also protect what you say during a caucus.
Federal Rule of Evidence 408 prohibits the use of statements made during compromise negotiations to prove or disprove the validity or amount of a disputed claim. The rule covers both settlement offers themselves and “conduct or a statement made during compromise negotiations about the claim.”3Legal Information Institute. Rule 408 Compromise Offers and Negotiations A court can admit the evidence for limited other purposes, such as proving witness bias, but not to establish liability or damages. If mediation fails and the case goes to trial, the other side generally cannot tell the jury what you offered or said during a caucus.
Rule 408 has limits. It is an evidence rule, not a secrecy rule. It stops the information from being used at trial. It does not stop the other party from publicly disclosing what happened in mediation or from discovering evidence through other channels just because it also came up during negotiations.
For broader protection, about a dozen states plus the District of Columbia have adopted the Uniform Mediation Act, which creates an actual privilege for mediation communications. Under the UMA, mediation communications are generally not subject to discovery or admissible in court, with narrow exceptions for things like threats of violence, plans to commit a crime, or professional misconduct claims. Many other states have their own mediation confidentiality statutes offering similar protection. The scope varies significantly by jurisdiction, so confirm what rules apply in your state before the session.
The Downsides Worth Knowing
Caucuses are not universally praised, and some mediators avoid them entirely. The concerns are worth understanding before you walk in.
The most common criticism is that private sessions give the mediator too much power. When the mediator is the only person who has heard both sides’ confidential positions, they can interpret messages, define issues, and steer the outcome. A mediator who is not scrupulous about neutrality can shade the way proposals are presented, emphasize certain risks over others, or push toward a result they think is right. The line between helpful reality-testing and inappropriate pressure is real, and not every mediator walks it perfectly.
There is also a perception problem. While the mediator is in the other room for 45 minutes, you are sitting there wondering what is being said about you and whether the mediator is taking sides. Even if the mediator is completely impartial, the extended private conversation with your opponent can feel unsettling. Good mediators manage this by keeping caucus lengths roughly balanced and checking in with the waiting party, but the discomfort is inherent to the format.
Heavy reliance on caucuses can also reduce mediation to a series of exchanged offers, stripping away the direct communication that distinguishes mediation from lawyers trading numbers. When parties never hear each other’s perspectives firsthand, they miss the chance to build understanding, acknowledge harm, or repair a relationship.
Caucuses by Video
Virtual mediation is now standard in many practice areas, and caucuses translate to the online environment through breakout rooms. The mediator, acting as video conference host, creates separate breakout rooms for each side before the session begins. When it is time to caucus, the mediator opens the rooms and each party receives a prompt to join their assigned space.4Financial Industry Regulatory Authority. Guide for Using Breakout Rooms in Virtual Mediation The mediator then joins one room, has their conversation, leaves, and joins the other.
Virtual caucuses can feel more abrupt. In person, you see the mediator leave and know they are heading next door. On video, the mediator simply disappears from your breakout room, and you wait. Platforms typically give a 60-second countdown before rooms close and everyone returns to the main session, so the transition back is not instantaneous either. If you are in a conference room using a shared camera, you may need to log in on separate computers to participate in breakout rooms, since shared connections sometimes cannot be split.
The confidentiality rules are identical. What you tell the mediator in a virtual breakout room is governed by the same ethical standards as an in-person caucus.
How to Prepare
You cannot fully control when a caucus happens or how the mediator runs it, but you can walk in prepared. The Fourth Circuit Court of Appeals, in its guidance for mediation participants, recommends giving careful consideration to what matters most to you in the dispute and how the specific issues connect to your broader interests and values before the session starts.5Fourth Circuit Court of Appeals. Preparing for a Mediation
Think through these questions before the mediation:
- What is your realistic range? Know your best realistic outcome and the worst you would accept. Having that in mind before the mediator asks saves time and produces better answers than thinking on the spot.
- What are your true priorities? Money is usually part of it, but consider what else matters: an apology, a future business relationship, a payment timeline, confidentiality of the settlement terms. The more the mediator understands, the more creatively they can work.
- What are your case’s weaknesses? Be honest about where your position is vulnerable. If you can identify those weaknesses before the mediator does, you will be less defensive during reality-testing.
- What can the mediator share? Decide in advance what information you are comfortable having conveyed and what must stay confidential. You can change your mind during the session, but a starting framework helps.
The same court guidance suggests entering mediation without rigid predetermined bottom lines, noting that fixed boundaries identified in advance “may limit one’s ability to profit from the mediation.”5Fourth Circuit Court of Appeals. Preparing for a Mediation A caucus works best when you stay open to information you did not have before the session started, including the mediator’s assessment of risks you had not considered. The goal is not to win the caucus. It is to use the private conversation to make a better decision about settling your case.