Coding endoscopic sinus surgery can be a real challenge, especially in an outpatient setting and especially because CMS keeps changing the rules. Clear and concise documentation is the key to ensuring proper reimbursement and reducing the risk of non-compliance. Even then, it takes a talented coder to translate the documentation and assign accurate medical coding.

Take note
Don't code from the list of operations, as it doesn't tell the whole story. Instead, refer to your treasured set of coding books, bundling resources and the actual documentation. Documenting endoscopic sinus surgery is all about the facts — the who, what, when, where and why. Here's what should be included in the operative note:

• the side(s) (unilateral or bilateral) on which the procedure(s) was performed;
• the procedure(s) done (noting which sinuses) and how (scope, open or submucosal);
• unique qualities;
• extenuating circumstances, such as heavy bleeding, repeat sinus surgery, diabetes and obesity; and
• if there was any tissue removal — CPT codes differ depending on whether there was tissue removal from the maxillary or sphenoid sinus.

Procedural scope
Many types of procedures fall under the category of endoscopic sinus surgery. Break the op report apart to ensure all billable codes are captured, modified correctly and sequenced appropriately. You should also read the body of the operative notes to make sure that what's described in "procedure performed" is described in the text as well.

Starting with the procedure that has the most value, select the primary diagnosis and procedure codes based on the sinuses involved. The diagnosis code will support the "why" and the procedure codes will support the "what." Sequencing multiple procedures is critical, especially if both unilateral and bilateral procedures are performed, as lower-paying procedures could trump higher-paying procedures if performed bilaterally.

Although not bundled in CCI, ethmoidectomy and sphenoidotomy codes (31254, 31255, 31287, 31288) are considered access to CSF (cerebrospinal fluid) leak and orbit decompression procedures, since the scope must go through the ethmoids and sphenoids to accomplish these procedures. For Medicare, you can code 31240 at the same time you code 31254 or 31255. CCI edits support the fact that this set of codes requires additional expertise and effort over and above ethmoid surgery. Private payors, however, may bundle 31240 into endoscopic sinus surgery codes and not pay for it separately.

For frontal sinusotomy, the documentation should describe ostitic bone removal between the frontal sinus and the supraorbital ethmoid cell. The note should include any work performed inside the frontal sinus ostium for enlargement or other reasons. A frontal sinusotomy can be done on a partially developed frontal sinus if it needs to be enlarged for drainage. If the surgeon only explores the frontal sinus while performing an ethmoidectomy, bill only 31255.

To bill 31276, the surgeon must perform a sinusotomy (opening the frontal sinus, for example). Entering the "frontal recess" isn't entering the frontal sinus. The frontal recess leads from the ethmoids to the frontal sinuses. Note that 31276 includes the endoscopic exam of obstructing frontal recess cells, polyps or scar tissue (including partially developed frontal sinuses), the delicate removal of intersinus septi from the dome of the ethmoid and skull base, and it may include the removal of ostitic bone between the frontal sinus and a supraorbital ethmoid cell.

When coding and billing a total ethmoidectomy, you must document the entrance and work on both the anterior and posterior ethmoid sinuses in the body of the operative note. If only the anterior ethmoids were done, the operative note should indicate a partial ethmoidectomy. If neither the posterior nor anterior were indicated, code for a partial (31254).

Note that endoscopic sinus surgery procedure codes have zero follow-up days in the Medicare fee schedule. However, additional procedures performed with FESS may alter the global period (septoplasty or turbinectomy, for example).

Turbinates
When billing for turbinate resection, make sure you use the diagnosis for turbinate hypertrophy (478.0) and nasal obstruction (478.1), as you must demonstrate the medical necessity of these procedures.

Report 30130 (Excision inferior turbinate, partial or complete, any method) for the partial or complete excision of the inferior turbinate. For this code, the entire inferior turbinate, mucosa and turbinate are excised. Bill this code bilaterally if both inferior turbinates are resected. If FESS surgery wasn't performed and a middle turbinectomy was done, bill 30999 (Unlisted procedure, nose).

Report 30140 (Submucous resection inferior turbinate, partial or complete, any method) for the submucous resection of the inferior turbinates. This means that the physician entered the mucosa, excised the inferior turbinate bone, slipped it out of the mucosa and left the mucosa behind. Bill bilaterally if both inferior turbinates are resected.

Excising or doing a submucous resection of the middle turbinates is considered access to the sinuses and, therefore, incidental to FESS surgery and not billable. Watch out for procedures that are automatically included in any surgical endoscopic procedures by convention or bundling, including:

• 31231 (Nasal endoscopy, diagnostic, unilateral or bilateral [separate procedure])
• 30115 (Excision nasal polyp(s), extensive)
• 30117 (Excision or destruction [e.g., laser], intranasal lesion; internal approach)
• 30999 (Unlisted nasal procedure for excision of middle turbinates)
• 31238 (Nasal sinus endoscopy, surgical; with control of nasal hemorrhage)

Navigational assistance
CPT code 61795 (Stereotactic computer assisted volumetric [navigational] procedure, intracranial, extracranial or spinal) is an add-on code. If the procedure is performed in an ASC, Medicare will only reimburse the physician, not the ASC. (Check if private payors have a different rule for this code.) Medicare doesn't bundle CPT 61795 into FESS codes for physician services, so list 61795 separately in addition to the primary procedure FESS code. Don't report 61795 alone, don't attach a modifier to it and, as always, make sure medical necessity is documented.