Purpose <p>Core clerkships are foundational learning experiences, yet variability in duration exists across medical schools. Many institutions adjust core clinical experiences as part of curricular modifications to meet evolving needs in undergraduate medical education. We investigated if shortened Internal Medicine (IM) and Surgery clerkship lengths or if clerkship sequence within the academic year would have any impact on NBME subject exam scores.</p> Methods <p>We examined four cohorts of third-year medical students from academic years 2017–2018, 2018–2019, 2019–2020, and 2021–2022. Individual student NBME subject exam data were compared, controlling for MCAT score and clerkship block sequence within the academic year.</p> Results <p>We found no statistically significant differences in IM or Surgery NBME subject exam scores between the traditional clerkship length (2017–2019) and shortened clerkship length (2019–2022) groups. Mixed-effect regression analyses that included MCAT and block sequence as additional covariates confirmed there were no statistically significant differences in IM or Surgery exam scores between groups. Despite no change in length, the Psychiatry (<i>p</i> = 0.012) and Pediatrics (<i>p</i> = 0.036) clerkships had increased scores post-intervention on the mixed-effects model. MCAT scores were predictive of overall NBME scores on both ANCOVA and regression analyses (<i>p</i>-values ranging &lt; 0.001 to 0.01). Finally, taking a clerkship later in the academic year was associated with increased NBME scores across all subjects (<i>p</i> &lt; 0.001).</p> Conclusions <p>Shortened clerkship length is not associated with lower performance on NBME subject exams. Clerkship sequence later in the academic year is associated with higher scores. Curricular reform resulting in reduced core clerkship duration may be undertaken without adverse impact on medical knowledge.</p>