Quality assurance is a routine and indispensable part of the work of the Medizinische Dienst der Krankenversicherung (MDK) (Medical Services of statutory health insurance bodies in Germany). To optimize the internal organisational processes, a quality assurance system (QAS), certified by EQ Zert, Ulm tan accredited certifier of the TGA), was implemented for the first time in one of the departments of the MDK, namely, the hospital department. Employees and management consider the advantages to be as follows: the aims of the department are clearly described, the processes are now self-evident and more strictly observed, overlaps to other fields of the company are defined. Both an Error Management System with follow up measures, and a project Management System to control projects have been implemented. The documentation system was standardized, and consequently relocating documents has become more streamlined. An MDK self-evaluation was performed as part of an internal audit. The audit showed that the QAS of the hospital department of the MDK in Hesse is indeed highly developed. It is anticipated that gradually other fields of the MDK will also be certified, to comply with the changing requirements.