Otolaryngology Coding Alert

Sift between CPT^®, NCCI instruction to get it down right.

Mohs surgery is a common and effective treatment for a variety of different skin cancers. The goal of Mohs surgery is to remove as much of the malignant skin as possible while preserving healthy skin. In order to do this, the surgeon will remove layers of skin at a time under microscopic guidance. Specifically, Mohs micrographic surgery is considered the most effective treatment for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).

You’ll also find that Mohs surgery is most exclusively performed by otolaryngology and dermatology practices. “Based on Medicare data from 2015, the most common body areas Mohs were performed in Florida were the head, neck, hands, feet, or genitals,”  relays Ronda Tews, CPC, CHC, CCS-P, AAPC Fellow, director of billing and coding compliance at Modernizing Medicine in Boca Raton, Florida.

That’s why it’s crucial that you’re familiar with all the various sets of guidelines and instruction on how to report Mohs micrographic surgeries. Use this reference guide to lay the coding groundwork for all your future Mohs surgery claims.

Discern Between Mohs, Other Dermatological Procedures

Where Mohs surgery differs from a typical excision procedure involving the integumentary system comes with the subsequent histological evaluation. Following the removal of the malignancy, the surgeon will “map and divide” the tumor into segments. Each segment is then placed in an individual tissue block for examination. The number of tissue blocks is important when determining Mohs CPT^® code selection.

Coder’s note: As the CPT^® manual range-specific guideline states, “it requires the integration of an individual functioning in two separate and distinct capacities: surgeon and pathologist.” The CPT^® manual goes on to instruct that “if either of these responsibilities is delegated to another physician or other qualified health care professional who reports the services separately, these codes should not be reported.”

Choose Your Codes

Mohs surgeries performed by an otolaryngologist will require that you select from the following code set:

• 17311 — Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (eg, hematoxylin and eosin, toluidine blue), head, neck, hands, feet, genitalia, or any location with surgery directly involving muscle, cartilage, bone, tendon, major nerves, or vessels; first stage, up to 5 tissue blocks
• +17312 — …each additional stage after the first stage, up to 5 tissue blocks (List separately in addition to code for primary procedure).

Bank on Useful NCCI, CPT^® Guidelines

When first gearing up to code a Mohs surgery, you’ll want to have all the relevant authoritative guidelines at your disposal. Of primary consideration should be the policy instated by the National Correct Coding Initiative (NCCI, or CCI) Policy Manual.

First, the NCCI Policy Manual reiterates CPT^® guidelines that “a single physician performs both the surgery and pathologic examination of the specimen(s).” The Policy Manual also elaborates on some NCCI edits that exist between 17311, 17312, and a plethora of skin biopsy and excision codes:

• “The Mohs micrographic surgery CPT^® codes include skin biopsy and excision services (CPT^® codes 11102-+11107, 11600-11646, and 17260-17286) and pathology services (88300-88309, 88329-+88332). Reporting these latter codes in addition to the Mohs micrographic surgery CPT^® codes is inappropriate.”

It’s guidelines such as these that outline the true importance of a reference tool such as the NCCI Policy Manual. That’s because if you didn’t get this explanation, you might feel comfortable using an overriding modifier such as modifier 59 (Distinct Procedural Service). But keep in mind that there are some instances where use of an overriding modifier is valid:

• “However, if a suspected skin cancer is biopsied for pathologic diagnosis prior to proceeding to Mohs micrographic surgery, the biopsy (e.g., CPT^® codes 11102-+11107) and frozen section pathology (CPT^® code 88331) may be reported separately utilizing modifier 59 or 58 to distinguish the diagnostic biopsy from the definitive Mohs surgery.”

The CPT^® manual relays a similar set of information in the range specific guidelines for 17311/+17312. Additionally, both the CPT^® manual and NCCI Policy Manual explain that it is appropriate to report repairs, grafts, and flaps separately with Mohs surgery codes.

Lastly, the NCCI Policy Manual helps to differentiate between acceptable uses of modifier 58 (Staged or Related Procedure or Service by the Same Physician or Other Qualified Health Care Professional During the Postoperative Period) instead of 59:

• “Although the CPT^® Manual indicates that modifier 59 should be utilized, it is also acceptable to utilize modifier 58 to indicate that the diagnostic skin biopsy and Mohs micrographic surgery were staged or planned procedures. Repairs, grafts, and flaps are separately reportable with the Mohs micrographic surgery CPT^® codes. (CPT^® codes 11100 and 11101 were deleted January 1, 2019.)”

Use Caution in Reporting +88314 with Mohs Codes

Your last guideline to consider comes when you’re determining whether it’s appropriate to report +88314 (Special stain including interpretation and report; histochemical stain on frozen tissue block (List separately in addition to code for primary procedure)) in addition to the Mohs surgical code. CPT^® explains that, for a routine frozen section stain, reporting +88314 is inappropriate:

• “Do not report +88314 with 17311-+17315 for routine frozen section stain [eg, hematoxylin and eosin, toluidine blue], performed during Mohs surgery. When a nonroutine histochemical stain on frozen tissue during Mohs surgery is utilized, report +88314 with modifier 59.”

If the surgical report does warrant coding +88314 in addition to 17311 or +17312, then CPT^® instructs that you should report one unit of +88314 for each special stain on each frozen surgical pathology block.