This research objective is to determine the optimal price break points for n­block tariff, because comparing non­linear pricing with uniform pricing on the basis of profit, n­block tariff outperforms two­part tariff, all unit discount price schedule, and uniform pricing. Although the merits of non­linear pricing are well documented, the attempt to practice the non-linear pricing in medical service sector has been relatively rare. The determination of the parameters under n­block tariff is the interesting decision making agenda for marketers. Under n­block tariff, the marketers should decide the optimal price break points and the optimal marginal price for each price zone. The results can be summarized as follows: The researchers found that mixture model can be the feasible methodology for determining the optimal number of n­block tariff and identifying the optimal segmentation criteria. We demonstrate the feasibility and the superiority of the mixture model by applying it to the database of medical examination. The results appear that the number of patients per month can be the optimal segmentation variable. And 6­block tariff is the optimal price break for this medical service.