Med/Arb is simply a combination of mediation and arbitration (see separate descriptions for each). JAMS has neutrals who can perform this unusual and sensitive role, acting first as a mediator then becoming an arbitrator. In a med/arb the parties first try to mediate the dispute with the chosen mediator/arbitrator as their mediator. If the parties are not able to come to a resolution of their own design through negotiations facilitated by the mediator, either the parties or the mediator will declare an impasse and halt the mediation process. At this point the process switches to become an arbitration whereby the mediator/arbitrator now becomes the arbitrator of the dispute. The steps in the arbitration process will depend on any prior agreements and the rules the parties are using. The arbitrator will then render an award resolving the dispute.
What is unique to this form of dispute resolution is that when in the role of the meditator, the mediator/arbitrator will have private discussions in caucus with the each of the parties and may hear confidential information that an arbitrator might not normally not hear. Thus this form of dispute resolution requires a neutral that is highly respected by all parties.
Med/Arb requires a person that is able to deal with the emotional issues standing in the way of settlement when in the role of the mediator and be able to see past the emotional issues to the facts and the law when in the role of the arbitrator.