The article develops a method of evaluating and diagnosing costs for event management in the form of a matrix that takes into account the directions of managing event processes of business entities (strategic management of event processes; event management of integration, transformation, and change; management of team building processes; management of business activities ) taking into account the phases of its formation and development (emergence phase, growth phase or "accelerated growth," stabilization and maturity phase, activity reduction phase or "restructuring") and provides for economists and analysts the possibility of identifying the key places of occurrence of these costs in the management system. The complex of these indicators refers to the following types of expenses: costs for researching the event services market and searching for information about event service providers, costs for data analysis, providing information support for event processes and creating a strategic plan, costs for progressive event software and technical support for strategic management event processes, costs for wages of employees involved in the strategic management of event processes, costs for conducting an advertising campaign in the foreign market, costs for a comprehensive study of the requirements of the internal and external environment regarding integration, transformation and changes, costs for changing the organizational structure of enterprise management , costs for wages of employees involved in the event management of integration, transformation and changes, costs for the progressive event, software and technical support for the event management of integration, transformation and changes, costs for the preparation, design and implementation of the integration operational and transformational processes for the purpose of optimization, costs for researching the requirements of the internal and external environment for team-building processes, costs for personnel involved in team-building organizational processes, costs for catering, costs for the entertainment part of team-building, transport and travel costs for team-building, costs for rent of premises and sites for team building, costs for design, design and decoration of premises, costs for renting inventory and equipment, audiovisual support, clerical support, reporting, costs for a motivational component, insurance costs, costs for researching the requirements of the internal and external environment for business communications, agency costs for searching and establishing contacts, costs for personnel involved in the planning and organization of business events, transport and travel costs for the purposes of business events, insurance costs, visa support, other related travel documents and, food costs during the trip, communication and information support costs, marketing costs, exhibition costs and presentation costs.