As hospital-based managers are being confronted with changing patterns of reimbursement, ranging from revenue generating to cost management, it is imperative that hospitals know the exact nursing costs associated with the actual care delivered to specific patients. Nursing care has traditionally been bundled into the room rate for patients. This approach is extremely limiting when facilities are negotiating per diem rates and capitated rate contracts. At Braintree Hospital Rehabilitation Network, the nursing department has developed and implemented an activity-based management system to determine the actual cost of nursing care provided to each patient. This approach, which differentiates nursing costs accurately by diagnostic group and by intensity of nursing care, has contributed to the hospital's success in negotiating individual patient contracts with insurers in the managed care environment that increasingly focuses on costs and outcomes. Another result has been to enhance the accuracy of the network's cost accounting system.