As from 2005 the specialized complex rheumatologic treatment can be assigned to the code category 8-983 (Multimodale rheumatologische Komplexbehandlung) of the OPS procedure classification system. Only by means of this specific procedure code, has an appropriate description and consideration in the G-DRG system of the common clinical practice in specialized rheumatologic hospitals/clinics become possible. The complex and multimodal treatment reflects the rheumatologic therapeutic standard for the treatment of inflammatory rheumatic diseases and non-inflammatory pain syndromes. The article focuses on the minimal criteria that have to be met for coding the OPS 8-983. Helpful practical instructions are given concerning how to implement the complex procedure into practice. Even though the newly introduced procedure code OPS 8-983 will not yet develop influence on the grouping process in 2005, other changes in the GDRG system lead to an improved economic valuation of rheumatological services in comparison to 2004.