Anesthesia Coding Alert

Question: A surgeon completed bilateral knee replacements and asked us to administer bilateral femoral nerve blocks for postoperative pain management. We coded 01402. However, we were told that when billing for anesthesiologists we cannot use modifier 50. What is the rule or guideline for this?

Virginia Subscriber

Answer: That is correct: you cannot use modifier 50 (Bilateral procedure) with anesthesia codes such as 01402 (Anesthesia for open or surgical arthroscopic procedures on knee joint; total knee arthroplasty). But you can report modifier 50 with nerve block codes. If your records support that the femoral block was administered bilaterally, you can definitely append modifier 50 to 64448 (Injection, anesthetic agent; femoral nerve, continuous infusion by catheter [including catheter placement]).

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.