Denial of CPT® 36415

We had a Workman's comp patient who had blood drawn at another facility. Our office was asked to redo the blood draw, and we used 36415. BCBS is the wc carrier, and is denying stating that 36415 is included in the global allowance for another procedure and is not separately billable. They said we should write-off or resubmit a corrected claim with a modifier. I'm not sure what modifier to use.

re: Denial of CPT® 36415

Resubmit a corrected claim with modifier 77 (Repeat procedure by another physician or other qualified health care professional).