For meeting the requirements for high quality and safe of care as well as efficiency and productivity of health systems, latter have to move towards job sharing, communicating and cooperating structures. This paradigm change must be supported through sustainable and semantically interoperable architectures for health information systems, especially for Electronic Health Record (EHR) systems as the core application in any eHealth environment. Advanced system architectures are characterized as being highly distributed, component-oriented, model-based, service-oriented, knowledge-based, user-friendly, lawful and trustworthy, based on a unified development process, a harmonized ontology and reference terminologies. Existing and emerging approaches for EHR systems are to be compared using the Generic Component Model (GCM) as architectural reference. Any system can be assessed according to GCM dimensions: transparent domain representation, composition/decomposition behavior and reflection of the systems' viewpoints as well as their components' interoperability level. All those aspects have to be interrelated for real systems analysis, design, implementation, and deployment by that way enabling the migration of different EHR approaches on the basis of GCM.