Question: What is the correct CPT® code for this surgery? Indications: Invasive ductal cancer status post mastectomy right with a small local recurrence in the incision along the chest wall. Procedures performed and description: Chest wall resection 3 cm x 6 cm. The provider incised the nodule on the right side of the chest and carried down to the chest wall. Post-procedure diagnosis: Ductal carcinoma of right breast [C50.911]. The office gave me 21601. I don’t believe that is correct because no bone was removed. AAPC Forum Participant Answer: You are correct in dismissing 21601 (Excision of chest wall tumor including rib(s)) as the correct code to describe this procedure for the reason you mention: The op note did not indicate the removal of anything other than the lesion. You would also not use 19301 (Mastectomy, partial (eg, lumpectomy, tylectomy, quadrantectomy, segmentectomy)) as the provider performed the procedure you describe post mastectomy. In this case, your best choice would likely be 11606 (Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter over 4.0 cm) for three reasons: