On June 27 2000, the German Self-Administration and lately the German Ministry of Health set the general conditions for a new reimbursement system for the inpatient hospital sector which is based nearly exclusively on lump-sum payments. The Association of Acute Rheumatology Hospitals (VRA) and the DRG-Research-Group, Münster University Hospital, conducted a multi-center trial which included 7266 cases from 22 different hospitals. The data were used to analyze how well the not yet German healthcare adjusted G-DRG system (version 1.0) accounts for rheumatologic diagnostics and treatment as well as problems of specialized hospitals. 7 Adjacent-DRGs covered 91% of all cases, 68% of all cases were grouped into only two different Adjacent-DRGs (169 Bone Diseases and Specific Arthropathies and 166 Other Connective Tissue Disorders). Groups with different complexity which are not appropriately covered by the existing G-DRG system could be identified. The data further revealed a systematically longer length of stay in rheumatology clinics opposed to the average length of stay in the data used for calculating the G-DRGs, due to different structures and procedures of the complex rheumatologic treatment. The results strongly supported the assumption that an accurate reimbursement of rheumatologic cases in the current G-DRG system 1.0 would not have been possible. Adaptations made in the new G-DRG Version 2004 can only partly solve these problems, despite an improved construction of the DRGs. In order to guarantee an appropriate reimbursement of rheumatology clinics from 2005 on, the G-DRG system must be adapted to specific rheumatological pathways and/or alternative or additional reimbursement systems have to be found.