To assess the value of the American Society for Reproductive Medicine Embryo Transfer Certificate Course in confidence and skill building for performing a live embryo transfer (ET). Prospective cohort study. Two-day simulation workshops of reproductive endocrine and infertility (REI) fellows from American Board of Obstetrics and Gynecology-approved training programs, using four different uterine models (A-D). None. Didactic and hands-on simulation training program. Primary outcomes included ET simulation scores of all exercises analyzed at various points of the training and self-assessed confidence before and after the completion of the Embryo Transfer Certificate Course based on a 6-point Likert scale and association of both with extent of prior live ET experience and year of fellowship. Data were collected for 78 REI fellows who completed the Embryo Transfer Certificate Course and demonstrated significant improvements in both skill and confidence. The data for a subset of 58 fellows who performed five direct transfers on both Embryo Transfer Certificate Course uterine models A and B demonstrated significant overall improvement in ET simulation scores between the first and fifth direct transfers. A separate data subset of 57 fellows who performed five afterload transfers for each exercise on all four uterine models demonstrated differences in difficulty among them. Embryo transfer simulation using the uterine A model was consistently the easiest. The ET simulation scores for fellows using the uterine B and C models showed a progressive and significant increase across the five afterload ETs. When using the uterine D model, ET simulation scores increased significantly between the first and second transfers but remained at the same level for the remaining three transfers. Except for uterus A, a significant increase in ET simulation scores between the first and last transfers was observed for fellows overall in all afterload transfers and for those fellows with <50 prior live transfers. Data for all 78 fellows demonstrate a significant gain of self-confidence for all parameters, with the highest overall increase (78%) observed for first-year fellows as well as for fellows of any year with no prior live transfer experience (109%). Fellows with the largest number of prior live ET experience started with higher confidence, which also increased significantly, although they had a lower gain in confidence compared with fellows with less experience. The American Society for Reproductive Medicine Embryo Transfer Certificate Course data analysis demonstrates the effectiveness of simulator-based ET training for REI fellows across the 3 years of training, regardless of prior experience with live ET.