The diagnosis procedure combination (DPC) of Japan started in April 2003. It is a unique "per day" payment system that evolved from diagnosis-related group and prospective payment system, which was a "per case" system. After a trial of two years, various undesirable problems of DPC have been revealed. A review of those problems in major diagnostic classifications (16) is in progress. The main problems are: 1) the medical institution-specific coefficient; 2) up-coding; and 3) consideration for expensive medical equipment such as during cardiac catheterization. The inclusive payment system is described and the problems of DPC are discussed.