The mediator must maintain confidentiality in all information revealed during mediation except where disclosure is required by law. All oral or written communications in mediation are confidential and inadmissible as evidence in any subsequent legal proceeding, unless both parties agree otherwise. The reason for the rule is to encourage people to talk openly and honestly, without fear of something said in mediation being used against them.

The mediator is permitted to meet and speak privately with any participant and his or her attorney. This usually happens when the mediator or an attorney or participant thinks it will help move the discussion toward a solution. This is called a "caucus."

Information obtained during caucus may not be revealed by the mediator to any other mediation participant without the consent of the disclosing party.