Starting July 5, you won't be able to resubmit denied claims. Transmittal 104 instructs carriers to deny any claims that are duplicates of claims they've already denied or medically reviewed. Also, if the carrier requested documentation on the claim but didn't receive any, the carrier should deny the repeat claim. Medical Coding experts express bewilderment at this documented change, since Medicare has never accepted resubmission of denied claims. You're supposed to appeal denials, not resubmit.