Electronic exchange of medical data between clinics and test centers makes the testing process more efficient, enables continuity of care record and reuse of medical data. The presented project employs HL 7 FHIR approach to model clinical concepts for the medical data exchange between a test center and different hospitals. Using a standard FHIR editor we have modeled 1226 observation profiles, 2396 commercial tests profiles that are mapped to 3249 production tests profiles. We have also defined a concept of an order and developed RESTfull API protocol to facilitate the ordering process. Now the data exchange system is in production and processes more than 20 000 test orders with more than 40 000 tests a day.