Reference
Dermatology Procedure Coding Guides
Skin biopsies, lesion destruction, excisions and repairs, Mohs stages and blocks, and the cosmetic-versus-medical split — what decides the code for each, and what the note has to record for it to hold.
Guides in this section
Skin biopsy
Skin Biopsy Coding: 11102 to 11107 in Dermatology Billing
How to code skin biopsies correctly: tangential, punch and incisional families, primary versus add-on units, and why the technique in the note decides the code, not the lesion.
Lesion destruction
Lesion Destruction Coding: 17000, 17003, 17004 and 17110
Destruction of premalignant and benign lesions coded correctly: 17000 and 17003 unit stacking, when 17004 replaces them, and how 17110 and 17111 differ.
Excisions and repairs
Excision and Repair Coding in Dermatology
Benign and malignant excision coding by site and excised diameter, plus when simple, intermediate and complex repairs are separately reportable.
Mohs CPT coding
Mohs Surgery CPT Coding: 17311 to 17315 and Stage Counting
Mohs micrographic surgery coding explained: first stage versus additional stages, tissue block add-ons, what is bundled into the Mohs code, and how repairs are reported.
Cosmetic vs medical
Cosmetic Versus Medical Dermatology Billing
How to separate cosmetic self-pay work from medically necessary dermatology on the same visit: consent, financial disclosure, coding and the compliance line you cannot cross.
Why dermatology procedure coding leaks money quietly
Most specialties lose revenue to denials, which are visible. Dermatology loses most of its revenue to undercoding, which is not. A destruction billed at one unit when nine lesions were treated pays cleanly. An excision coded from the lesion diameter instead of the excised diameter pays cleanly. A sixth Mohs block never reported pays cleanly. Nothing in the remittance says anything is wrong.
That is why these guides are written around the measurement and the count rather than around the code list. The code is almost never the hard part — the hard part is whether the number that drives it was captured in the room, in a field a biller can see.
How to use these guides
- Each guide covers what determines the code, what the note must record, and where the common error sits.
- Documentation requirements are written as what the record must show, not as phrases to paste into a template.
- Undercoding and overcoding are treated as equally serious. One costs you money now, the other costs you more later.
- These are references, not coding advice for a specific claim. Payer policy varies by contract and by MAC jurisdiction, and it changes.
Frequently asked questions
Which dermatology procedure is most often coded wrong?
Lesion destruction, because the add-on unit count is the whole value of the claim and it depends on a number being carried from the note to the claim intact.
Do you review how our practice currently codes these?
Yes. The free claims audit samples recent claims against the documentation behind them and reports undercoding as well as risk, since undercoding is usually the larger number.
Can our providers use these guides directly?
They are written for that. The documentation sections are the ones worth putting in front of clinical staff, because that is where the code is actually decided.