The Committee on Diabetic Nephropathy revised the classification of diabetic nephropathy in view of the current status of eGFR and CKD in Japan. To make revisions for the classification of diabetic nephropathy 2014, the Committee carefully evaluated the report of the Research Group on Diabetic Nephropathy, Ministry of Health, Labour, and Welfare of Japan. The major revisions made were as follows: 1. eGFR can be used for the evaluation of GFR; 2. In stage 3 (overt nephropathy), A and B were combined; 3. Stage 4 (renal failure) was defined as GFR less than 30 mL/min/1.73 m2, regardless of albuminuria; and 4. The importance of differential diagnosis was stressed in all stages.