Mark is an active arbitrator in the field of employment disputes and labor relations. He serves on arbitration panels for the American Arbitration Association, the Federal Mediation and Conciliation Service, and the Financial Industry Regulatory Authority.

Mark is a federally-certified workplace EEO investigator, serves as an Administrative Judge for the EEOC and issues final agency decisions under contract with the U.S. government.

Mark has mediated hundreds of cases involving employment disputes, labor relations, and civil rights. In addition to private litigated cases, Mark serves on the mediation panels for the American Arbitration Association, the U.S. Equal Employment Opportunity Commission, the Nuclear Regulatory Commission, and the Financial Industry Regulatory Authority.