Dermatology Coding Alert

Coding experts unveil the key to biopsy pay

If you're confused about when you should report a biopsy and when you should choose an excision code, ask these three simple questions to avoid this common dermatology denial trap.

1. Why did the dermatologist remove the skin abnormality?

When your dermatologist sees a patient who has a suspicious lesion, such as a mole that changed shape over time or has irregular borders, the dermatologist must remove that lesion, says Carole Violette, CPC, CDC, a clinic manager at Yakima Valley Dermatology/Derm Attractions in Yakima, Wash.
 
Caution: Just because the dermatologist removed the lesion, he didn't necessarily perform a biopsy. Dermatologists send both excisions and biopsies to pathology, but you should report a biopsy (11100, Biopsy of skin, subcutaneous tissue and/or mucous membrane [including simple closure], unless otherwise listed; single lesion) only if the dermatologist obtains a diagnosis (for instance, 172.x, Malignant melanoma of skin)   from the pathology report, says Pamela J. Biffle, CPC, CCS-P, an independent consultant in the Dallas/Fort Worth area and an American Academy of Professional Coders instructor.

If the dermatologist actually performed an excision and not a biopsy, you should report the procedure with an excision code (11400-11646)
 
2. How much of the lesion did the dermatologist remove?

The lesion's size or depth usually dictates the removal method, Violette says. Derm-atologists usually perform superficial shaves to completely remove lesions such as surface moles, she says. But in other instances, the dermatologist will perform an excision to obtain a portion of a more severe lesion, such as a cyst-like lesion below the skin's surface.

In this instance, the dermatologist excises a segment of the lesion and sends the specimen to pathology. But should you code an excision or a biopsy?

Answer: You should report a biopsy code because the dermatologist took only a portion of the lesion for a pathology diagnosis. Therefore, in this case, you should bill code 11100 for a single lesion, and add-on code +11101 (... each separate/additional lesion [list separately in addition to code for primary procedure]) if the dermatologist takes a specimen from more than one lesion.

Don't miss: Because add-on codes refer to the procedures the physician performed in addition to a primary service/procedure, you must never report them as stand-alone codes or you will see denials, coding experts say.
Make sure you look at CPT's parenthetical instructions, which usually tell you which procedure codes you can use the add-on code with.

Extra: If the documentation does not clearly state the specimen's size (for instance, the whole lesion or just a sampling), you can always wait for the details of the pathology report before you determine which code to use (11100 or 11400, Excision, benign lesion including margins, except skin tag [unless listed elsewhere], trunk, arms or legs; excised diameter 0.5 cm or less), says Ellen Wallpe, CPC, coding consultant in Eliot, Maine.

3. Did you append the correct modifiers?

Don't make the mistake of reporting 11100 and 11101 when the physician performs another procedure, such as an excision (11400). You will face denials if you report excisions and biopsies together, because CPT considers the biopsy a component of 11400, according to CPT 2004.
 
Tip: If a dermatologist performs a lesion excision and a biopsy of a different site on the same day, don't forget to append modifier -59 (Distinct procedural service) to the biopsy code to avoid a denial, says Vanessa Rivera, RHIT, CPC, a coding specialist at Bend Memorial Clinic in Bend, Ore.
 
Example: The dermatologist performs a biopsy of a lesion on a patient's arm and excises a different lesion on the patient's neck during the same visit. You would report 11100 and 11420 and append both modifier -51 (Multiple procedures) and modifier -59 to the biopsy code.

Explanation: You should attach modifier -51 to the biopsy code (11100) because it is the lesser-valued procedure (valued at $90), and append modifier -59 to 11420 because the biopsy is a component of the excision, coding experts say. 

In some instances, the dermatologist may decide to bi-opsy the separate lesion on a different day, Rivera says.
In this case, if the patient returns for the biopsy procedure within the 10-day global period, you should append modifier -79 (Unrelated procedure or service by the same physician during the postoperative period) to the biopsy code (11100).