Against the background of the interoperability hurdles, the legislator has commissioned gematik to define standards for interfaces in hospitals. With a transition period of 24 months, hospitals have been obliged since June 30, 2021, to use only gematik-certified information technology systems in hospitals (ISiK). A uniform standard for all based on HL7 FHIR should not only facilitate data exchange within hospitals, but also overcome sector boundaries in the future.