Early alignment of residency and fellowship milestones can predict surgical trainee success.

• Significant alignment found between PGY-5 general surgery and year-1 vascular surgery fellowship competencies in professionalism, patient care, medical knowledge, and interpersonal skills.
• For every 1-unit difference in residency milestones, fellows showed mean differences of 0.49 to 0.64 units in competencies.

These insights can guide patient selection and identify trainees who may need additional support during transition.

• Surgical skills like systems-based practice did not align significantly, indicating areas for potential improvement.