How Do I Prepare For USMLE® and COMLEX® Shelf Exams? Preparation for USMLE® and COMLEX® Shelf Exams. What Are The Shelf Assessment Exams? Purpose of the shelf examination. How Should I Prepare For The Shelf Assessment Exams? Use these techniques to better prepare for the USMLE®, COMLEX®, NBME®, and NBOME® shelf assessment examinations.