The archiving and exchange interface for practice management systems of the Kassenärztliche Bundesvereinigung, defined by FHIR (Fast Healthcare Interoperability Resources) profiles with extensions, describes a new opportunity for medical practitioner to change the system provider. The expectation is to transfer an entire database of a legacy system to another system without data loss. In this paper the potential loss of data is analyzed by comparing parameters. The results show that during an import on average 75% of the parameters per profile are supported and on average only 49% of the reviewed parameters, existing in the exporting system, could be represented based on the interface specification.