With the advancement of Intelligent Transportation Systems (ITS), the current and future Emergency Medical Services (EMS) systems are characterized by real-time response, specialization, and decentralization. In order to provide real-time response of medical services, several components are essential, such as dispatching, routing, emergency facilities, and patient?s medical history. This paper proposes CORBA-based GIS-T framework for the dispatching and assignment of medical vehicles for emergency services via wireless communication. The framework combines distributed object computing, Geographic Information Systems for Transportation (GIS-T), and transportation models in a single system, thus provides flexibility and interoperability among existing medical service systems. The framework utilizes the concept of distributed systems and capabilities of CORBA to design objects and dynamically updated medical facilities information in order to provide ambulances with up-to-date information. A real roadway network is used in the numerical experiments to illustrate dynamic aspects of the proposed system.