Otolaryngology Coding Alert

Improper coding for diagnostic endoscopies can sometimes result in the loss of significant reimbursement. Among the reasons for this are using the lower-level 31231 code (nasal endoscopy, diagnostic, unilateral or bilateral [separate procedure]) for all diagnostic endoscopies. Depending on what the otolaryngologist did and documented, it may be appropriate to bill either 31233 or 31235 (see definitions below) if the diagnostic endoscopy went beyond the areas covered by 31231 and scoped the maxillary or sphenoid sinuses.
 
Several factors make billing 31233 (nasal/sinus endoscopy, diagnostic with maxillary sinusoscopy [via inferior meatus or canine fossa puncture]) or 31235 (nasal/sinus endoscopy, diagnostic with sphenoid sinusoscopy [via puncture of sphenoidal face or cannulation of ostium]) complicated. First, the documentation must be precise, not only identifying the specific anatomic areas viewed by the endoscope but also detailing how access to the sphenoid or maxillary sinus was achieved.
  
Second, 31233 and 31235 may be confused with their surgical counterparts, 31256 (nasal/sinus endoscopy, surgical, with maxillary antrostomy) and 31287 (nasal/sinus endoscopy, surgical, with sphenoidotomy). This can result in downcoding (for example, a 31256 to a 31233) and receiving less payment than the otolaryngologist should have obtained. Upcoding (31235 to 31287) may also occur. To use these codes correctly, clinical differences must be understood.

 
Endoscopic codes 31231, 31233 and 31235 describe diagnostic procedures. "These three codes are about viewing, not doing," says Barbara Cobuzzi, MBA, CPC, CPC-H, a coding and reimbursement specialist and president of Cash Flow Solutions, a medical billing company in Lakewood, N.J. "The procedures described by these codes evaluate, but do not treat, the patient."
 
The basic diagnostic endoscopy code, 31231, describes an endoscopic inspection of the nasal cavity and turbinates, as well as the inferior meatus and the middle meatus, all of which typically are easily accessed through the nose.
 
"This is not the case for 31233 or 31235," Cobuzzi says. "These diagnostic procedures are more serious because there is no easy access to the maxillary or sphenoid sinuses. Unless the patient has had previous sinus surgery and, as a result, there is an opening that allows easy access to the sinus, the procedure usually is performed in the operating room, especially a 31235."
 
If the patient does not have an existing opening, the otolaryngologist may need to puncture the inferior meatus or the canine fossa for a maxillary endoscopy, Cobuzzi adds.
 
Similarly, to inspect the sphenoid sinus(es) of a patient who does not have an opening, the otolaryngologist may need to puncture the sphenoidal face (bone) or insert a tube into the sinus opening, i.e., cannulate the ostium.
 
Note: Although the sinusoscopies described in 31233 and 31235 are surgical procedures (because they involve puncturing the inferior meatus or the sphenoidal face), the procedure as a whole is considered diagnostic because, in both cases, the endoscopy and the puncture or cannulation is performed only to allow the otolaryngologist to view the sinus. If additional work is performed, the procedure becomes surgical and these codes should not be used.
 
Not only do 31233 and 31235 more accurately describe the scoping of the maxillary or sphenoid sinuses but they also reimburse at a higher rate than 31231. According to the CMS (formerly HCFA) fee schedule, 31233 (maxillary) is assigned 5.00 transitioned, non-facility RVUs by Medicare's 2001 fee schedule, but 31231 gets only 2.98. 31235 (sphenoid) is assigned 5.57 RVUs.
 
Note: Codes 31233 and 31235 are not bundled with each other, which means they may both be billed if performed during the same session. The second procedure (31233) will be reduced by 50 percent as a multiple procedure. Some carriers may require the use of modifier -51 (multiple procedures), so you should check with yours for individual guidelines. If either 31233 or 31235 is performed in conjunction with the basic scope, 31231 should not be billed, as it is a separate procedure and would be included in the more involved nasal endoscopy code.

 
Another advantage of correctly billing 31233 or 31235 is that both may be billed with modifier -50 (bilateral procedure) appended if the otolaryngologist inspects the sinuses on both sides. Unlike 31231, which states "unilateral or bilateral" in its descriptor and therefore cannot be billed with modifier -50, 31233 and 31235 should pay at 150 percent of the fee schedule rate when performed on both sides and appropriately documented.
 
For example, if an otolaryngologist performs sinusoscopies on both the left and right maxillary sinuses, 31233 should be billed with modifier -50 to inform the carrier that the otolaryngologist performed the procedure twice, says Teresa Thompson, CPC, an otolaryngology coding and reimbursement specialist in Sequim, Wash. The bilateral procedure should be valued at 7.50 RVUs, i.e., 150 percent of 5.0 RVUs, the unilateral fee for 31233; 31231 has 2.98 RVUs.
 
"People often have sinus problems on both sides," Thompson says, "so many otolaryngologists perform more bilateral than unilateral diagnostic sinus endoscopies." As a result, a lot of additional payment may be obtained if coded correctly.

 
Based on what is viewed, the otolaryngologist may decide to do more than look.
 
For example, if the physician decides to create an opening to allow the maxillary sinus to drain (a maxillary antrostomy), the procedure ceases to be diagnostic and becomes surgical, and surgical endoscopy code 31256 is appropriate.
 
"A coder may be confused when reading an operative report (or a patient's chart, if the endoscopy was performed in the office) that includes work on the maxillaries or sphenoids," Cobuzzi says. She adds that sometimes 31233 may be billed inappropriately, when in fact the otolaryngologist did more than just explore the sinuses, but actually performed the antrostomy.
 
Even more common, Cobuzzi says, is incorrect upcoding from a diagnostic to a surgical procedure. The physician or coder may assume that because the maxillary or sphenoids are involved, the surgical codes should be used. The fact that a puncture was performed may further influence the incorrect selection of a surgical code, Cobuzzi says.
 
For example, a documented trocar puncture directly into the sphenoid sinus may be confused with a surgical endoscopy with sphenoidotomy, resulting in the incorrect billing of 31287, when 31235 should have been billed. "A 31235 becomes a 31287 only when you remove the sphenoid face or any bone," Cobuzzi says.

 
To bill 31233 or 31235 correctly, otolaryngologists need to dictate clear and accurate documentation that indicates which sinus was inspected, Thompson says: "Doctors can't just say they did an endoscopy and then try to bill for either of these two procedures. If a diagnostic maxillary or sphenoid endoscopy is performed, but the documentation reads the same as it would for a diagnostic ethmoid endoscopy, 31231 should be billed."
 
Claims for 31233 or 31235 with documentation that states only that a sinusoscopy was performed, for example, are unlikely to be looked at favorably by an auditor.
 
The documentation should clearly indicate how access to the appropriate sinus was achieved. Often, Thompson says, this information is left out of the patient's chart (or operative report). "Shortcut documentation that only notes which sinus was accessed but does not mention how, isn't good enough," Thompson says.
 
For example, if a physician performs a maxillary sinusoscopy (31233), he or she needs to document how the approach to that sinus was managed -- usually a puncture through the inferior meatus, for instance. A statement in the patient's chart might read:   
 
"Because of prior surgery, scope could be advanced into the maxillaries." Thompson says document the medical necessity for going to the maxillary sinus in the first place.
 
Similarly, for a sphenoid sinusoscopy (31235), the otolaryngologist must document either a puncture or cannulation of ostium to explain how the sphenoid was accessed and must provide the appropriate diagnosis codes to indicate the medical necessity.