Abstract: An audit selection method (10) for commercial casualty policies (such as workers' compensation, employer's liability, and general liability policies) can include the steps of determining (14) a probability of under-reported exposure for a given policy (12) using classification modeling, identifying (24) a source of under-reported exposure using classification modeling, and selecting an audit protocol (28, 30, 32) effective or most effective in uncovering an under-reported exposure based on the probability determined and the source of under-reported exposure identified. Identifying the source of under-reported exposure can be done by identifying at least one among payroll increases, uninsured subcontractors, and misclassified occupations as examples. Determining the probability can be done by classifying the given policy according to a likelihood that an actual exposure for the given policy exceeds an exposure upon which an estimated premium was based requiring an additional premium for the given policy.