Third-party payers reimburse for physician services performed by nurse practitioners, if the services are within the scope of practice of a nurse practitioner and the payers’ rules are followed. However, some hospitals and trauma services have been reluctant to bill the services of nurse practitioners they employ or to hire nurse practitioners, because the rules are complex, vary from payer to payer, can be difficult to find, and because operations are not always set up so that nurse practitioners’ services are bundled in ways which conform to the rules. Medicare has developed detailed rules on billing nurse practitioners’ services, but neither Medicaid nor commercial payers necessarily follow Medicare’s rules. The situation is further complicated by wide variations in state law governing nurse practitioner scope of practice and requirements for physician collaboration. Despite all of these variables, it may be worth the time and effort to sort out the requirements for utilizing nurse practitioners and billing for their services, considering the limitations on residents’ hours, the data on quality of nurse practitioners’ clinical services and the potential for generating revenue. This article describes the legal and business issues, provides the general rules for billing nurse practitioners’ services, and provides a plan for obtaining third-party payment for nurse practitioners’ services on trauma teams.