A system and method for modeling healthcare utilization based on usage data from physician claims, hospital claims, and pharmacy claims. The method includes extracting from a claims file the portion of the data from a base period that is relevant to modeling healthcare utilization in a target period by computing a utilization score based on the usage data. The models may be used concurrently by calibrating them with the base period equal to the target period and they may be also be used prospectively by calibrating the models with the target period representing a future time period.