CPT® 99401

Get denial from highmark BCBS for CPT® 99401 and the reason showing as " Inorder to process the claim additional information is requuried. The claim should be submitted with a valid procedure and an associate diagnosis". This is a payable CPT® per BCBS fee schedule and we billed with dia V65.49.
Not sure what is the exact issue. Anyone pls help me to solve the issue.

re: CPT® 99401

Please advise