I received a rejection from Blue Cross Blue Shield of Illinois that I've never seen before and not sure how to fix. It says: (A3) Missing or invalid information. DUPLICATE FILE ID-CANNOT USE TWICE IN 12 MONTHS (21)
I've gotten so few rejections that I'm not sure where to start, though I expect to be on hold forever if I call BC. Any clue as to what this means? Not even sure what File ID refers to And is "A3" or "21" referencing a certain section of the claim form? Box 21 is the dx code...but that doesn't seem like File ID...and it's a typical code.
Would greatly appreciate any help in sleuthing this one. Thanks.