Background and Objectives: The COVID-19 pandemic began interrupting family medicine residency training in spring 2020. While a decline in scores on the American Board of Family Medicine In-Training Examination (ITE) has been observed, whether this decline has translated into the high-stakes Family Medicine Certiufb01cation Examination (FMCE) is unclear. The goal of this study was to systematically assess the magnitude of COVID-19 impact on medical knowledge acquisition during residency, as measured by the ITE and FMCE. Methods: A total of 19,101 initial certiufb01cation candidates from 2017 to 2022 were included in this study. Annual ITE scores and FMCE scores were reported on the same scale (200-800) and served as the outcome measure. We conducted multilevel regression analysis to determine ITE score growth and FMCE scores compared to cohorts prior to COVID-19. Results: During COVID-19, the increase in ITE scores from postgraduate year 2 (PGY-2) to PGY-3 was 25.5 points less, representing a 57.6% relative decrease; and from PGY-3 ITE to FMCE, it was 8.6 points less, a 12.7% relative decrease, compared with cohorts prior to COVID-19. FMCE scores were 6.6 points less during COVID-19, representing a 1.2% relative decline from the average FMCE score prior to COVID-19. Conclusions: This study found nonsubstantive COVID-19 impact on FMCE scores, but a considerable knowledge acquisition decline during residency, especially during the PGY-2 to PGY-3 period. While COVID-19 impacted learning, our ufb01ndings indicated that residencies were largely able to remediate knowledge deufb01cits before residents took the FMCE.