Otolaryngology Coding Alert

Your otolaryngologist may push you to bill 17304-17310 for the extensive work she performs with Mohs reconstructive surgery, but make sure you understand Mohs micrographic surgery fundamentals before you report these codes.

 Although dermatologists normally perform Mohs micrographic surgery (17304-17310), some otolaryngologists want to bill for this high-paying service. Otolaryngologists, however, usually provide postoperative reconstructive surgery, which you should bill with codes for laceration repair (12000-13000 series), adjacent tissue transfer (14000 series), or flaps and grafts (15000 series), rather than Mohs micrographic surgery codes.

Mohs Requires Dual Tasks

 CPT does not restrict 17304-17310 to dermatologists. But to bill these codes, the Mohs surgeon must be both the surgeon and the pathologist, says Julie Robertson, CPC, an otolaryngology coding and reimbursement specialist for University ENT Specialists in Cincinnati. "You should use the Mohs codes only if the physician performs both components," she says.
 
Part of the confusion over using these codes is a misunderstanding of what Mohs surgery is. In a nutshell, the doctor removes a thin layer of the lesion, freezes it and immediately checks the margins under a microscope to see if they are clear of cancer, says Pamela J. Biffle, CPC, CCS-P, an independent consultant in the Dallas/Fort Worth area and a professional medical coding curriculum American Academy of Professional Coders-approved instructor. If the margins are not clear, the surgeon takes another layer sometimes several times until she removes a layer that shows no cancer cells under the microscope. In this case, because she acts as a single physician in two integrated but separate and distinct capacities surgeon and pathologist CPT specifies that you would report Mohs micrographic surgery.

Use 11600-11646 When ENT Performs Surgery Component Only

On the other hand, if either of these responsibilities is delegated to anotherphysician who reports her services separately, the use of the Mohs micrographicsurgery CPT codes is inappropriate, according to CPT. "For instance, if the physiciansends the sample to a pathologist to perform the work, the surgeon would bill for lesion excision and reconstruction, and the pathologist would bill the pathology codesseparately," Robertson says.

When an otolaryngologist performs excision only, some coders wonder if they may use 17304-17310 appended with modifier -52 (Reduced services) to indicate that the physician elected to perform less than the full procedure. But correct coding requires coding to the highest specificity possible, rather than approximating a procedure. Because codes exist for reporting the surgeon's part, reporting 17304-17310-52 to indicate that your otolaryngologist provided the surgical component is inappropriate, Biffle says. "Mohs is a package deal: The physician either does the excision and fresh frozen tissue technique or he doesn't."

The high reimbursement for Mohs codes may tempt otolaryngologists who spend a lot of time removing multiple layers to use 17304-17310 rather than the lower-paying excision codes, such as 11641 (Excision, malignant lesion including margins, face, ears, eyelids, nose, lips; excised diameter 0.6 to 1.0 cm). But Mohs codes pay more because they reflect the large overhead costs of owning the freezing units and extensive clinical pathology equipment required to conduct the pathological component of 17304-17310. For instance, the practice expense RVUs (8.09) for 17304 comprise more than half of the nonfacility total RVUs (16.00) for the code. "Most otolaryngologists do not have the equipment necessary to perform Mohs," Biffle says.

Re-Excision Does Not Equal Mohs Surgery

High equipment costs for Mohs prompt many otolaryngologists to make arrangements with hospitals that allow physicians to provide same-day excision and pathology. In these cases, the surgeon removes the tissue, which is taken to the hospital where pathology freezes the section, examines it and usually calls the otolaryngologist with the report within 15 minutes. That way, the surgeon may proceed with additional excisions depending on the pathology report, Biffle says. "Don't allow this arrangement to confuse you." The technique involves two physicians, so each doctor reports his work.

Unfortunately, CPT views same-operative-session excisions and re-excisions as one procedure, Biffle says. Therefore, if an otolaryngologist performs multiple same-day excisions on the same patient, he may report only one code based on the final widest excised diameter achieved at the end of the day's session.

Same-day re-excision example: If a surgeon excises a 0.5-cm lesion from a patient's cheek (11640, Excision, malignant lesion including margins, face, ears, eyelids, nose, lips; excised diameter 0.5 cm or less) and widens the margins to 0.8 cm after receiving a malignant report (11641, ... excised diameter 0.6 to 1.0 cm), he should report only the code that reflects the excision's final measurement 0.8-cm final diameter = 11641.

On the other hand, you may report separately a re-excision that occurs at a subsequent operative session. If the surgeon in the above example does not perform the re-excision until day four, she should report the excision with 11640 and the re-excision with 11641 appended with modifier -58 (Staged or related procedure or service by the same physician during the postoperative period) to indicate a staged procedure performed during the 10-day global of the original excision (11640), Biffle says.

Plastic Repair Warrants Full Payment

Another area that confuses coders is reporting reconstruction. Because the postoperative reconstruction may involve removing small amounts of tissue from the same site multiple times, you may think the repair is Mohs surgery. But otolaryngologists often repair Mohs excisions performed by dermatologists, Robertson says. "If a patient has had a Mohs procedure and comes to us for repair, we always double-check the margins before doing the reconstruction."

Prior to closing any defects, Robertson's otolaryngologists biopsy the defect's margins and send it to pathology. "If the excision did not adequately remove the cancer, the otolaryngologist re-excises the area until pathology shows the margins are clear," Robertson says.

For Mohs reconstructive surgery, you should assign the appropriate repair, flap or graft code. Remember to bill adjacent tissue transfers once per defect site, no matter how many flaps the otolaryngologist makes.

Defect example: Mohs surgery for a basal cell carcinoma of the chin leaves a 5-sq-cm defect. The surgeon uses two regional rotation flaps to close the defect. Although the otolaryngologist made two flaps, you should bill based on the number of defect sites: One 14060 (Adjacent tissue transfer or rearrangement, eyelids, nose, ears and/or lips; defect 10 sq cm or less). If the surgeon repairs two defects, bill the second one appended with modifier -59 (Distinct procedural service) to indicate a separate site.

Mohs surgery has zero global days, so no overlap occurs between the surgery and reconstruction.