Increasing demands for provider profiling have led to the growth of health information services units within payers and health plans. An important decision faced by these groups is whether to buy or build the information infrastructure necessary to support the activities of the department. The article offers an overview of a system that was collaboratively designed and built by Blue Cross and Blue Shield of Iowa and the Dartmouth Medical School. A case study illustrating the flexibility of the information system in adapting ambulatory care groups to the fee-for-service payer industry is reviewed.