The National Hemophilia Foundation (NHF) recognizes the importance of phase IV post licensing clinical studies as defined by the Food and Drug Administration (FDA). This mechanism facilitates continuing data collection to examine and guarantee product safety and should also expedite the approval process by the FDA of new therapies which are important to the hemophilia community. Therefore, the NHF urges physicians to participate in phase IV studies and to complete patient data forms in a timely manner for submission to the FDA. In addition, we urge industry (in their consultation with FDA) to develop clinical reporting forms which minimize the efforts of HTC staff in fulfilling FDA requirements for licensure. (NHF medical leadership would be pleased to help towards this end). Financial compensation should be provided for any study that requires data collection that exceeds more than a few minutes of staff time per patient. Post licensure studies are not to be considered as a substitute for clinical trials to seek answers to important scientific questions.