The author presents a review on the DRG system, basic terms used in the system, structure of the IR DRG code, information on revision activities in the system and expected trends after the introduction of the DRG system. The paper refers to the presentation from the seminar of ÚZP OP VZP in Prague on September 25, 2003.

        Key words: IR DRG system – MDC – DRG groups – inlier – outlier – relative weight – basic tarif – GROUPER IR DRG – code IR DRG – MCC – CC