Anesthesia Coding Alert

Question: A surgeon completed bilateral knee replacements and asked our pain management specialist to administer bilateral femoral nerve blocks for postoperative care. We coded 01402 with modifier 50, but were told we cannot use modifier 50 with anesthesia codes. If that’s correct, how should we code the service?

Minnesota Subscriber

Answer: You cannot use modifier 50 (Bilateral procedure) with anethesia codes such as 01402 (Anesthesia for open or surgical arthroscopic procedures on knee joint; total knee arthroplasty). You can, however, report modifier 50 with nerve block codes.

If the record supports that your provider administered the femoral blockbilaterally, you can definitely append modifier 50 to 64448 (Injection, anesthetic agent; femoral nerve, continuous infusion by catheter [including catheter placement]) since it is a nerve block code.

The postoperative block reporting depends on payer preference, so verify the correct tactic before filing the claim. Options would be:

• 64448-50 as1 unit on a single claim line
• 64448 as 2 units on separate lines
• 64448-50 modifier on one line and 64448 on the second.