This article contains a complete analysis of a patient-based cost-information system. We have incorporated an extended hospital cost-allocation system and the adjusted clinical DRG system, (DRG = Diagnosis Related Groups) into an integrated hospital cost-information system for both in- and outpatient. This method is sufficiently aggregated for economic analysis and also specific for medical physicians and therefore useful for internal budgeting. The analysis is applied to three Dutch general hospitals. A comparison of the treatment and cost profiles of clinical patients and ambulatory patients is given. The results are important as a decision-supporting system for the allocation of inputs.