Otolaryngology Coding Alert

Question: A surgeon insists on billing bilateral nasal endoscopies 31233, 31235 and 31237 with modifier 50 and two units. Although some carriers prefer that we report bilateral procedures on two lines with modifier 50 on the second line, I have never heard of reporting 31233-50 x 2. Several Medicare carriers prohibit the use of multiple units for reporting these bilateral procedures, but I cannot find this policy from any commercial carriers. Where can I find a non-Medicare publication that addresses the proper reporting of these codes?


New York Subscriber


Answer: Although commercial payers may vary on their bilateral surgery billing requirements as you indicate above, using modifier 50 (Bilateral procedure) with two units isn't appropriate. This method reports the code four times, rather than two times. For instance, reporting bilateral maxillary sinusoscopy (31233, Nasal/sinus endoscopy, diagnostic with maxillary sinusoscopy [via inferior meatus or canine fossa puncture]) as 31233-50 x 2 represents two bilateral nasal endoscopies or the physician performing four endoscopies.

Some payers will not process modifier 50 claims on one line. They instead require you to report bilateral procedures on two lines, such as

31233
31233-50. But you should use one unit on each line based on the private payer's rule, not CPT.

Some insurers specify that one unit is the way to go. For example, Montana Medicaid instructs when using modifier 50 to -report only one unit of service in FL 46.- Regence Blue Shield of Idaho says, -Procedure codes eligible for modifier 50 should be billed as one line item with -1- in the units field.-

Several correct-coding books also address modifier 50 use. All of them refer to using modifier 50 as a single item. None of them discuss using two units, a silence that implies that doing so would be incorrect.

Coding With Modifiers by Deborah J. Grider, CPC, CPC-H, CCS-P, offers the following advice:

- Insurance carriers do not universally accept modifier 50 for reporting, and you can report with HCPCS modifiers (LT and RT) rather than modifier 50.
- Use modifier 50 with a one-line item.
- Do not use modifiers LT and RT when modifier 50 is applicable. In The Modifier Clinic, Lolita M. Jones, RHIA, CCS, gives these modifier 50 instructions: Use modifier 50 -to report bilateral procedures that are performed at the same operative session as a single line item. Report the appropriate five-digit code describing the first procedure.- Identify that the physician performed a second (bilateral) procedure by adding modifier 50 to the procedure code. -You must not submit two items to report a bilateral procedure.-

The AMA's Principles of CPT Coding echoes the above advice: -Unless otherwise identified in the listings, bilateral procedures that are performed at the same operative session should be identified by adding the modifier [...]