Frequently asked coding questions: Answered

By Alexander Miller, MD, February 1, 2020

Recently, the Academy’s coding staff and I have received several coding questions that others may have considered, but not asked. Below is a series of coding concerns followed by detailed answers. I hope that they may resolve some of your unasked questions.

Question: When multiple biopsies (CPT 11102-11107) are done on different sites of a diffuse skin rash, a bullous dermatosis, or a suspected panniculitis, should one be reporting one biopsy only, or the number of separate biopsies that are actually done?

Answer: When biopsies are done at separate anatomic sites, regardless of whether they are of distinct, unrelated lesions, or of separate locations of a presumed single type of eruption (such as a drug eruption, bullous dermatosis, panniculitis), one may individually report each biopsy. The CPT Assistant, in October 2004, referring to the now inactive old biopsy codes 11100 and 11101, stated the following: “When a biopsy is performed on each of several different lesions or sites on the same date, each biopsy may be reported separately, as appropriate.” The November 2019 CPT Assistant offers examples of multiple biopsies done on individual, separate lesions that are presumed to be an expression of one entity, such as a panniculitis.

Conclusion: Multiple biopsies done on separately identifiable sites are separately reportable. However, since the individual biopsies would be reported under one and the same ICD-10 diagnosis code, it would be best to specify the distinct anatomical sites of the biopsies in the medical record.

Example: Two separate incisional biopsies are done on distinct, non-contiguous cutaneous to subcutaneous nodules. The first biopsy is reported as CPT 11106, and the second, as CPT 11107 (additional incisional biopsy).

Question: What if multiple biopsies of a contiguous large lesion, such as a suspected broad lentigo maligna, are done? Would one report each individual biopsy, or just one biopsy?

Answer: When one contiguous lesion within one anatomical unit is multiply biopsied, only one biopsy code is reportable. CMS NCCI guidelines under Section C: Medical/Surgical Package state that if a single lesion is biopsied multiple times, only one biopsy code may be reported with a single unit of service. If multiple lesions are non-endoscopically biopsied, a biopsy code may be reported for each lesion appending a modifier, indicating that each biopsy was performed on a separate lesion.

Example: Three separate tangential biopsies are done at different sites of a broad atypical pigmented lesion on a cheek. Only one biopsy code, 11102, is reportable.

Question: When a surgical defect is partially closed with an intermediate repair and the rest of the defect is closed with a full-thickness skin graft, would one report both the intermediate repair and the graft?

Answer: The coding depends upon the source of the graft. CPT describes full-thickness grafts as: “Full thickness graft, free, including direct closure of donor site.” If the graft is a “kite graft,” then one would only report the full-thickness skin graft. However, if one reduces the defect with an intermediate repair, harvests the graft from a distant site, closes that donor site, and then applies the graft, then both the intermediate repair and the full-thickness skin graft are separately reportable.

Example: A scalp defect is reduced with an excision of a triangle of adjoining skin and a layered closure of the resulting defect, leaving a portion unapproximated. The excised triangle of skin is applied as a full-thickness skin graft (“kite graft”) to cover the remaining surgical defect. Although the original surgical defect is partially reduced with an intermediate repair of the graft donor site, this procedure is considered a harvesting of the graft and closure of the donor site. Consequently, only the full-thickness skin graft is reportable.

Question: When I excise a cyst, is it appropriate to use the diameter of the cyst for excision code selection, as opposed to the maximum excision diameter of the excised skin overlying the cyst?

Answer: The CPT defines excision as follows: “Code selection is determined by measuring the greatest clinical diameter of the apparent lesion plus that margin required for complete excision (lesion diameter plus the narrowest margins required equals the excised diameter).” The diameter of the cyst (plus the anatomical location) determines code selection.

Example: You excise an epidermal inclusion cyst located on the back through a narrow fusiform incision encompassing a central pore. The measured cyst diameter is 1.5 cm. You report CPT 11402, excision, benign, trunk, excision diameter 1.1-2.0 cm.

Question: Does a debeveling procedure done after a Mohs surgical excision constitute “debridement of wound edge,” and thus justify coding for a complex repair (CPT 13100-13153)?

Answer: The 2020 CPT partially defines complex repairs as: “Complex repair includes the repair of wounds that, in addition to the requirements for intermediate repair, require at least one of the following: exposure of bone, cartilage, tendon, or named neurovascular structure; debridement of wound edges (e.g., traumatic lacerations or avulsions).”

Consequent to this definition, intermediate repair criteria must first be satisfied. Relevant to dermatology, that typically means that a layered closure is done. Then, a further criterion for complex repair must be met. With respect to debridement, the November 2019 CPT Assistant declares the following: “Debridement is considered a separate procedure only when gross contamination requires prolonged cleansing, when appreciable amounts of devitalized or contaminated tissue are removed, or when debridement is carried out separately without immediate primary closure.” None of these criteria are typically met in a Mohs surgical setting.

Example: You excise a cheek basal cell carcinoma with Mohs surgery. You repair the defect two days later, at which point you gently debride the wound with gauze and verticalize (“debevel”) the wound edges by trimming off the beveled tissue. You then excise adjoining skin to form a fusiform defect shape, minimally undermine the edges and do a 4.5-cm-long layered repair. You report an intermediate repair, cheek (face), 2.6–5.0-cm length, CPT 12052.

Question: An excision was done on the cheek. A complex repair extended onto the ear. Would one code for a repair on the face or on the ear?

Answer: Code selection is based upon the site of the defect that is repaired. In this case, that is the cheek.

Example: A nasal sidewall surgical defect is formed into a vertical fusiform shape coursing along the nose and adjoining cheek, which is extensively undermined, pulled onto the nose and sutured as a layered closure. Although most of the undermining and tissue movement comes from the cheek, the repaired defect is on the nose. An appropriate complex repair, nose, CPT code is reported.

Question: May one report a simple repair for a Mohs surgical defect that is electrocauterized but not closed? This is based upon the following CPT verbiage in the simple repair definition: “This includes local anesthesia and chemical or electrocauterization of wounds not closed."

Answer: Electrocauterization of any wound without closure does not qualify as a simple repair. For one thing, “simple repair” has the word “repair” in it. That should tip one off that a surgical repair is essential for meeting the criterion for “simple repair.” The CPT provides the following definitive instructions under the repair (closure) section: “Use the codes in this section to designate wound closure utilizing sutures, staples, or tissue adhesives.” Further clarification follows under definitions: “Simple repair is used when the wound is superficial; e.g., involving primarily epidermis or dermis, or subcutaneous tissues without significant involvement of deeper structures, and requires simple one-layer closure.”

Example: All repairs, simple, intermediate, and complex, require a simple one-layer closure as a component of the repair.

Question: I approximated wound edges with buried dermal interrupted stitches and then further secured the skin edges with adhesive tape strips. Should I report an intermediate (layered) repair?

Answer: The above constitutes a simple repair. The CPT includes the following in the simple repairs definition: “Wound closure utilizing adhesive strips as the sole repair material should be coded using the appropriate E/M code.” This means that wound approximation with tape strips does not count as a “layer” of closure. In this vignette, the buried sutures constitute a one-layer closure: simple repair.

Example: A non-undermined surgical defect is closed with buried dermal-subcutaneous stitches and the surface skin is secured with cyanoacrylate glue. This constitutes a layered, intermediate repair. Simple repair includes wound approximation with “tissue adhesives (e.g., 2-cyanoacrylate)” (CPT).

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