CPT code 15787: Abrasion, each additional four lesions

Key takeaways

CPT code 15787 is an add-on code for skin abrasion, and it can never be billed on its own.

CPT 15786 covers only the first lesion, so 15787 starts at the second one. Each unit then covers up to four more lesions.

Modifier 51 never belongs on 15787, because add-on codes are exempt from it by AMA convention.

Each unit of 15787 is priced separately, and the exact lesion count in the note is what supports those units.

CPT code 15787 is the add-on code for skin abrasion after the first lesion. Each unit of it covers up to four more lesions treated in the same session. The American Medical Association (AMA) marks the code with a plus symbol, so it never travels alone on a claim.

The official descriptor reads: Abrasion; each additional four lesions or less (List separately in addition to code for primary procedure). Dermatologists, plastic surgeons, and aesthetic providers report it whenever one session treats more than a single lesion.

Almost every problem with this code starts with the count. Report one unit too few and you hand back revenue you earned. Send 15787 without its primary code and the line comes straight back.

CPT code 15787 at a glance

How 15786 and 15787 split the lesion count

CPT 15786 covers the first lesion and nothing else. Its descriptor reads Abrasion; single lesion (e.g., keratosis, scar), so one unit accounts for lesion one.

CPT 15787 picks up the count from there, in groups of four. That makes the second lesion treated the first lesion the add-on covers. The two codes are inseparable on a claim, because 15787 carries no value without 15786.

Use the table below to turn a lesion count into billable units.

The “or less” wording matters. A partial group still counts as a whole unit, so round up rather than down.

Take a session that treats nine lesions. CPT 15786 covers lesion one. One unit of 15787 then covers lesions two through five, and a second unit covers six through nine. That claim reads one unit of 15786 plus two units of 15787.

Add-on codes also sit outside the multiple procedure payment reduction. Standard codes billed on the same day get discounted, while 15787 does not. Other lesion-count add-ons work the same way.

Modifier 51 never belongs on a 15787 line

Modifier 51 does not go on 15787, ever. Add-on codes are exempt from it by AMA convention, so appending it triggers a payer edit and stalls the payment. Other modifiers still apply, depending on what happened in the treatment room.

The fix for a modifier 51 denial is quick. Strip the modifier from the add-on line and resubmit the claim. The bundling edits behind these rejections come from the National Correct Coding Initiative (NCCI). Its NCCI edits treat add-on codes as their own category.

Our roundup of software for plastic surgery practices shows how documentation, photos, and billing fit together.

What Medicare pays for each 15787 unit

Medicare prices every unit of 15787 separately, and there is no single national figure to quote. The rate comes from the Physician Fee Schedule, published by the Centers for Medicare and Medicaid Services (CMS). It moves with your locality and with the place of service.

Look up your own locality before you quote a figure to anyone. The CMS lookup tool returns the allowed amount for your Medicare Administrative Contractor (MAC) and place of service. Rates also change every January, so a saved number goes stale fast.

Private payers usually set their rate as a percentage of the Medicare schedule. Some negotiate a separate fee schedule instead, so read the contract before you assume anything.

Cosmetic abrasion sits outside Medicare cover altogether, which means the patient pays. Agree that in writing before the appointment. An advance beneficiary notice.

Which ICD-10 codes support a 15787 claim

The diagnosis has to explain why the skin needed abrading. A code that only restates the procedure will not carry the claim. The table lists diagnoses that commonly pair with abrasion work.

Treat those as examples rather than a coverage list. Payers differ on abrasion, and cosmetic intent gets denied whatever the CPT code says. Check the payer’s Local Coverage Determination (LCD), then write the clinical reason into the record.

What the procedure note has to prove

The note has to prove two things: that abrasion was the technique used, and how many lesions it covered. Everything else on the claim follows from those two facts. Strong HIPAA-compliant documentation habits then protect the practice when a payer asks for the chart.

These elements belong in every abrasion note:

• Total lesion count: state the exact number treated, never a range. “Twelve lesions” supports three units of 15787. “Approximately ten to fifteen lesions” supports none.
• Lesion identification: give each lesion a location, such as right cheek or left forearm, plus its size, type, and appearance.
• Procedure description: confirm abrasion was the technique, and name the instrument, such as a wire brush, diamond fraise, or sandpaper.
• Medical necessity statement: explain why abrasion suited the condition recorded in the paired ICD-10 code.
• Provider attestation: the treating clinician signs and dates the note. Mid-level providers billing under a physician must meet the supervision rules that apply.
• Photographs: before and after images back up a high lesion count when a payer asks. Have the photo consent form signed first.

Where those details live matters as much as whether they exist.

Keep the counseling record next to the procedure note as well. Good patient compliance notes show the patient was briefed on the procedure, the risks, and aftercare. That history supports a medical necessity argument later.

Where 15787 shows up in daily practice

Any session that abrades a second lesion opens the door to 15787. Some situations generate a single add-on unit, others generate five. These are the ones that come up most:

• Acne scar treatment: widespread post-inflammatory scarring across the face or trunk often means ten or more sites. Each scar counts as a distinct lesion, so map them before you start.
• Seborrheic keratosis removal: older patients often present with numerous keratoses across the scalp, back, or chest. Once abrasion treats a second one, the add-on applies.
• Actinic keratosis management: field treatment of sun-damaged skin runs up high counts quickly. The backs of the hands, the forearms, and the face are the usual sites.
• Wart treatment: patients with several plantar or common warts qualify once a second wart is abraded in the same visit.
• Scar revision: post-surgical revision across multiple small scar sites can qualify, provided the note documents abrasion as the technique.

Aesthetic practices see plenty of these sessions, with lesions spread over several areas of the body. Record the map at consultation. That beats rebuilding it from memory a week later.

The denials that hit 15787 most often

Nearly every 15787 denial traces back to five causes, and none of them are clinical. The table pairs each error with the correction that clears it.

None of those corrections help if the lesion count never reaches the biller. Practices that keep the note and the invoice on one record skip the rekeying step. That step is where counts usually go missing. Tracking denials by code pair, rather than by single code, then shows whether the problem is systemic.

How a 15787 claim actually moves

Knowing the path helps you spot where a claim stalls. It runs through five steps.

1. The provider writes the note and states the exact lesion count.
2. The coder turns that count into units: one 15786, plus one 15787 for each group of up to four.
3. The claim leaves the practice, usually through a clearinghouse, with both codes on it.
4. Payer edits check that the primary code is there and that no modifier 51 sits on the add-on line.
5. The payer prices each unit separately, then pays or denies the line.

Steps two and four cause most of the damage. A note that says “multiple lesions” cannot become units. A template that adds modifier 51 will keep doing it on every claim.

Run this check before the claim goes out

• Is 15786 on the same claim as every 15787 line?
• Does the unit count match the lesion count in the note, rounded up?
• Is modifier 51 absent from the add-on line?
• Does the ICD-10 code establish medical necessity, rather than cosmetic intent?
• Is the treating clinician’s signature on the note?
• Do the photographs, if any, match the count you billed?

Six questions take about a minute per claim. A medical coding cheat sheet pinned near the billing desk keeps the add-on rules in front of whoever is submitting.

The AAPC code lookup is a useful second opinion on add-on conventions and NCCI edits. Documentation standards for med spa compliance line up closely with what those edits expect to see.

How 15787 differs from the dermabrasion codes

Dermabrasion resurfaces an area of skin. Abrasion treats named lesions, one at a time. That difference decides which code family the claim comes from, and it is the mistake coders make most often here.

Dermabrasion codes cover mechanical resurfacing across a facial region, for concerns like acne scarring or wrinkling. If the whole face was resurfaced, 15780 describes that work, not a stack of lesion counts. Other integumentary add-ons.

Related CPT codes

• CPT code 17250 — Chemical Cauterization of Granulation Tissue
• CPT code 15788 — Chemical peel facial epidermal
• CPT code 15792 — Chemical peel nonfacial epidermal
• CPT Code 15821 — Lower eyelid blepharoplasty

How Pabau keeps 15787 claims clean

In most practices the lesion count lives in the procedure note. The claim then gets rebuilt by hand in a separate billing system. Every rekeyed count is another chance to lose an add-on unit.

Pabau, practice management software for dermatology and aesthetic practices, keeps both on one patient record. Our dermatology EMR software holds the treatment note, the before and after photos, and the invoice in the same file. Your coder works from the note itself, so the documented count is the count that reaches the claim. A clean claim carries the code, the modifiers and the diagnosis in agreement, and needs no rework before payment. If the encounter included an assessment and a plan, the evaluation and management component needs its own documentation.

Pabau’s claims management then checks the insurer details on a claim before it leaves the practice. Basic data problems get caught in-house instead of coming back as a denial two weeks later.

Keep lesion counts and claims on one record

Pabau holds the procedure note, the photos, and the invoice in a single patient file. Your coder bills the count the clinician documented, so add-on lines like CPT 15787 stop coming back.

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Conclusion

Three habits keep 15787 paid. Put 15786 on the same claim, write an exact lesion count in the note, and keep modifier 51 off the add-on line. None of that is difficult. It just has to live in the workflow instead of somebody’s memory.

The practices that get this right treat the count as a documentation job, not a billing job. Fix the note and the units follow. Book a demo to see how Pabau keeps the lesion count, the photos, and the claim on one patient record.

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