The objective of the study was to determine net costs of four potential preconception cystic fibrosis (CF) carrier screening strategies, and to identify the most important cost-related parameters. An estimate was made of the costs of screening carried out during general practitioner (GP) consultations, and screening carried out during group educational sessions. Two test strategies were evaluated: single-entry two-step (SETS) and double- entry two-step (DETS). Several sensitivity analyses were performed. Under the baseline assumptions, SETS screening during GP consultations was the least expensive (net costs US dollar 1,111,354 per year). The sensitivity analysis showed that the costs depend greatly on the estimated lifetime costs of care for a CF patient and the strategy used to inform the target population. Adaptations could be made to the screening program, resulting in economic savings while the primary goal of the screening--to enable participants to make an autonomous informed choice--is guaranteed.