Question: I’m coding a maxillary antrostomy. The doctor documents a small amount of tissue removed from the maxillary sinus. Can I bill as 31267? Virginia Subscriber Answer: An operative report is necessary in order to reach a definitive answer. You will need to provide further documentation of what constitutes a “small amount of tissue” in order to decide between codes 31267 (Nasal/sinus endoscopy, surgical, with maxillary antrostomy; with removal of tissue from maxillary sinus) and 31256 (Nasal/sinus endoscopy, surgical, with maxillary antrostomy). In order to report code 31267, the surgeon must remove tissue from within the maxillary sinus, not from the ostium (maxillary sinus opening). Additionally, the physician should document what type of tissue (mucosa, polyps, excessive crusting) was removed. Unfortunately, there are no definitive guidelines to determine what “amount” of tissue warrants the reporting of code 31267. However, the physician must, at the very least, document access to the maxillary sinus and the removal of a clinically significant amount of tissue.