The process of submitting an already-graded card to a different grading service for re-evaluation, typically without cracking the slab open. Most major services (PSA, CGC, BGS, SGC) offer a cross-over service that will only assign the new label if the card achieves at least the previous grade.

Cross-grading is common when one service is perceived to bring stronger market premiums for a specific issue (e.g., PSA for vintage baseball, CGC for trading cards in some markets).