Pulmonology Coding Alert

Question: I'm new to coding, and I still don't get add-on codes. What is their main function? Could you give an example that applies to pulmonology?

Texas Subscriber

Answer: The main function of add-on codes is to support a primary service that the physician or other health care professional has rendered. These codes are reimbursable when you report in addition to the primary code. It's easy to spot an add-on code in your CPT® manual: just look for a plus sign (+) symbol to the left of the code. A phrase in their descriptors would also remind coders to "List separately in addition to code for primary procedure."

A typical add-on code for pulmonology is +31633 (... with transbronchial needle aspiration biopsy[s], each additional lobe [List separately in addition to code for primary procedure]). You would use this code when a pulmonologist obtains a transbronchial needle aspiration (TBNA) of a lymph node from each lobe separate from the lobe from which an initial TBNA was obtained (31629, ... with transbronchial needle aspiration biopsy[s], trachea, main stem and/or lobar bronchus[i]).

Important: Never report an add-on code without its primary procedure code, or else the payer will not reimburse your claims. For instance, bill the endobronchial ultrasound code +31620 (Endobronchial ultrasound [EBUS] during bronchoscopic diagnostic or therapeutic intervention[s] [List separately in addition to code for primary procedure]) only in addition to another allowable bronchoscopy procedure (31622-31646). CPT® 31636 (...with placement of bronchial stent[s], [includes tracheal/bronchial dilation as required], initial bronchus), on the other hand, should always accompany +31637 (...each additional major bronchus stented [List separately in addition to code for primary procedure]).

Example: A patient with a chest CT scan showing right paratracheal and right hilar lymphadenopathy undergoes transbronchial needle aspirations with the assistance of endobronchial ultrasound. The right paratracheal and right hilar lymph nodes are biopsied. You would code 31629 for the right paratracheal node biopsies, +31633 for the right hilar node biopsies and +31620 for the EBUS used during the bronchoscopy. The two lymph node groups are in different "lobes" allowing the use of +31633.