A family physician removes a pigmented lesion from a patient's upper back on a Tuesday. She writes "excised 1 cm nevus, closed with sutures" in the procedure note and the charge drops to billing the same afternoon as 11401 with diagnosis D22.5. Nine days later the pathology report comes back: basal cell carcinoma. Nobody sees it in billing, because the claim is already paid. The practice has just under-coded a malignant excision as a benign one, used a diagnosis that contradicts the record, and lost the difference in payment. It happens in nearly every primary care practice we audit.
Skin lesion removal coding is a small number of procedures with a large number of ways to get them wrong. The physician has to decide what was done, the note has to carry a measurement taken before the cut, and the coder has to wait for a pathologist before the code can be final. When any one of those three steps is skipped, the claim is either wrong or unsupported.
A few terms for readers who do not code. Excision means the lesion is cut out full thickness through the dermis and the wound is closed. Destruction means the lesion is ablated in place by freezing, burning, laser or chemical, and there is nothing to send to pathology. A shave removal takes the lesion off at or above the dermis without full-thickness excision. A biopsy removes a piece of tissue for diagnosis, not to remove the lesion. Each has its own code family, and the families are not interchangeable.
Key takeaways
- Choose the code family from what was done to the lesion (excision, destruction, shave, biopsy, paring, skin tag removal), not from what the lesion turned out to be.
- Excision codes are sized by the excised diameter: the lesion's largest diameter plus twice the narrowest margin, measured before the excision.
- Excisions split into benign (11400 to 11446) and malignant (11600 to 11646) series, and the pathology report decides which one, so the claim waits for pathology.
- Simple closure is included in an excision; intermediate and complex repairs are separately reportable.
- The diagnosis code has to match the final pathology, and Medicare covers removal of benign lesions only when the note documents a medical reason.
Picking the code family
The first decision is the procedure itself, and it belongs to the physician, who should say plainly in the note which of these happened. Excision of a benign lesion is 11400 to 11446, arranged by body area (trunk, arms and legs; scalp, neck, hands, feet and genitalia; face, ears, eyelids, nose, lips and mucous membrane) and then by size. Excision of a malignant lesion is 11600 to 11646 with the same structure. Both include a simple closure and carry a 10-day global period, meaning routine follow-up in that window is not separately billable.
Destruction of premalignant lesions, almost always actinic keratoses, is 17000 for the first lesion and 17003 for each of the second through fourteenth; fifteen or more is 17004 reported alone, without 17000 or 17003. Destruction of benign lesions other than skin tags, which in primary care usually means warts and seborrheic keratoses, is 17110 for up to 14 lesions and 17111 for 15 or more. Destruction of a malignant lesion is 17260 to 17286, by site and size, and is uncommon in primary care because most physicians excise what they think is malignant.
Three more families come up. Skin tag removal is 11200 for up to and including 15 lesions and 11201 for each additional 10. Shave removal of an epidermal or dermal lesion is 11300 to 11313, by site and size, and does not use margins because there is no excision. Skin biopsy since 2019 is 11102 and 11103 for tangential technique, 11104 and 11105 for punch, and 11106 and 11107 for incisional, with the first code for the first lesion and the second for each additional. Paring of corns and calluses is 11055 to 11057 by count.
The common mistake here is the physician who freezes a lesion, writes "removed," and the coder picks an excision code. Removed is not a coding term. Ask for the method.
Measuring before the cut
Excision codes are sized by the excised diameter, which CPT defines as the greatest clinical diameter of the lesion plus the margin required for complete excision. In practice that is lesion diameter plus twice the narrowest margin, because the margin is taken on both sides. A 1.2 cm nevus excised with 0.2 cm margins has an excised diameter of 1.6 cm, which lands in the 1.1 to 2.0 cm size band, 11402 for the trunk.
The measurement has to be taken and documented before the excision. Skin contracts as soon as the incision releases tension, and a pathology report that says the specimen measures 1.3 cm is describing a shrunken specimen, not the excision. Coders may not upgrade a size from the path report, and they cannot supply a margin the physician did not record. If the note says "1 cm nevus excised" with no margin, the excised diameter is 1.0 cm and the code is 11401, which is one band lower than the same work documented properly.
Ask physicians to record three numbers in every excision note: lesion diameter, margin on each side, and the final length of the closed wound. The first two set the excision code. The third sets the repair code if the closure is more than simple.
Closure, multiple lesions and the same-day visit
Simple closure, meaning a single-layer closure of skin, is bundled into every excision code. Intermediate repair, which involves layered closure of deeper subcutaneous tissue and superficial fascia, is separately reportable with 12031 to 12057, and complex repair with 13100 to 13153, both sized by the length of the repair and grouped by body area. A 3.0 cm layered closure on the trunk after excising a 1.6 cm lesion is 12032 (2.6 to 7.5 cm) billed alongside 11402. The note must say layered or describe the deep sutures; "closed with 4-0 nylon" alone is a simple repair.
Multiple lesions removed at the same visit are each coded separately by their own site and size. Medicare applies its multiple procedure payment reduction automatically, and some payers want modifier 59 or XS on the second and later excisions to show distinct lesions; check the payer's edit response before assuming. Repairs of multiple wounds in the same body area group and repair class are added together into one repair code, which is the one place where lengths are summed rather than coded separately.
An office visit on the same day as a lesion removal is payable only if the visit addressed something beyond the decision to remove the lesion and the lesion itself, and then it carries modifier 25. A visit scheduled to remove a wart, where the note discusses only the wart, is 17110 alone.
Waiting for pathology and picking the diagnosis
This is the step that most practices skip, and it is why the opening example goes wrong. Excision codes require the coder to know whether the lesion was benign or malignant, and only pathology can say. Destruction codes do not have this problem because there is no specimen, which is one reason the wart and actinic keratosis claims can go out the same day.
The workflow we recommend is a pathology hold. Any encounter with an excision or a biopsy is placed in a hold status in the practice management system, not in the claim queue. The coder works a daily list of held encounters, matches each to the returned path report in the EHR, finalizes the CPT series and the diagnosis, and releases the claim. Most dermatopathology turns around in three to ten days, so the hold costs little in days in accounts receivable and prevents the under-coding, the contradictory diagnosis and the corrected claim that would otherwise follow.
| Pathology result | Common ICD-10-CM | CPT series for excision | Note |
|---|---|---|---|
| Melanocytic nevus | D22.0 to D22.9 by site | 11400 to 11446 | Benign series even if malignancy was suspected before excision |
| Seborrheic keratosis | L82.1 (inflamed L82.0) | 11400 to 11446, or 17110 if destroyed | Coverage depends on documented symptoms |
| Actinic keratosis | L57.0 | 17000, 17003, 17004 if destroyed | Premalignant, covered without symptoms |
| Basal or squamous cell carcinoma | C44.- by site and type | 11600 to 11646 | Malignant series; margins often larger |
| Uncertain behavior on pathology | D48.5 | Payer policy varies; many follow benign series | Use only when the pathologist says uncertain behavior |
| No pathology available | D49.2 | Not applicable to excision | Unspecified behavior; appropriate for destruction without a specimen |
Two diagnosis rules cause most of the denials. D48.5 (neoplasm of uncertain behavior) is a pathologist's conclusion, not a placeholder for "we don't know yet"; using it before pathology returns is a coding error. And Medicare's National Coverage Determination 250.4 covers removal of benign skin lesions only when there is a medical reason documented, such as bleeding, pain, intense itching, inflammation, obstruction of an orifice, restriction of vision, or a clinical change that raises concern for malignancy. A benign lesion removed because the patient did not like it is cosmetic, is not covered, and the patient should have signed an Advance Beneficiary Notice before the procedure so they can be billed.
A worked example, start to finish
A 58-year-old established patient comes in for a blood pressure follow-up and mentions a spot on the left forearm that has grown and bled twice. The physician adjusts the antihypertensive, documents the assessment, then measures the lesion at 0.8 cm, plans 0.3 cm margins, and excises it with a layered closure that measures 2.2 cm. The specimen goes to pathology. On the encounter: 99213 with modifier 25 for the hypertension work, and a pathology hold on the procedure.
Eight days later pathology reads invasive squamous cell carcinoma. The excised diameter is 0.8 plus 0.6, or 1.4 cm, on the arm: 11602 (malignant, trunk, arms or legs, 1.1 to 2.0 cm). The layered closure is 12031 (intermediate repair, trunk and extremities, 2.5 cm or less). Diagnoses: C44.629 for squamous cell carcinoma of the skin of the left upper limb, linked to both procedure codes, and I10 linked to the visit. Had the physician excised without recording margins, the code would have been 11601, and had the claim gone out on day one as benign, it would have been 11401 with D22.6 and a corrected claim later.
If you want to know how often this happens in your own practice, a targeted review of last year's 114xx claims against their path reports is a two-hour job and one of the pieces of our revenue leakage audit. Our coding courses walk new coders through exactly this sequence with practice cases.
Questions we hear
The physician excised a lesion she was sure was malignant, and pathology came back benign. Which series?
Benign. The excision series follows the pathology, not the suspicion. The clinical concern belongs in the note as the medical reason for removal, which is what supports coverage, and the malignant series would be wrong.
Can we bill a biopsy and an excision of the same lesion on the same day?
No. When the whole lesion is excised, the biopsy is part of the excision. A biopsy code is for taking a sample of a lesion that is left in place or of a different lesion. Two lesions, one biopsied and one excised, are separately reportable with a distinct-lesion modifier.
Do we need pathology before we can bill 17110 for a wart?
No. Destruction leaves no specimen, so there is nothing to wait for. Code the destruction, use the wart diagnosis (B07.8 or B07.9 for most, B07.0 for plantar warts) and release the claim.
What to do this week
- Pull last quarter's claims for 11400 to 11446 and check whether any had a pathology report showing malignancy; correct any that should have been the 11600 series.
- Add three fields to the excision procedure template: lesion diameter, margin per side, and closed wound length, with a method line for excision, shave or destruction.
- Create a pathology hold status in the practice management system and route every excision and biopsy encounter to it.
- Give the coder a daily held-encounter list and a target of releasing each claim within two business days of the path report.
- Review your Medicare contractor's benign lesion coverage article and post the covered symptom list where physicians document.
- Confirm the front desk knows when an Advance Beneficiary Notice is needed for a cosmetic removal.
