Dermatology billing that separates cosmetic from medical.

A dermatology medical billing company really earns its keep on the details: how many lesions, what size, and the bright line between what's medically necessary and what's cosmetic. A single afternoon can include a necessary excision, a round of destructions, a cosmetic filler, and a Mohs case. Mix those charges up on one claim and you're looking at denials and refund demands — often months later, after the patient already paid cash for the cosmetic part.

Destructions and the lesion-count ladder

Destruction of premalignant lesions typically starts with 17000 for the first lesion and 17003 for each additional lesion through 14; 17004 covers 15 or more in a single session. Benign destruction codes sit in a different family (often 17110/17111 depending on count). Mixing premalignant and benign counts on the wrong CPT is a frequent scrubber catch. Document lesion type and count clearly — "treated several AKs" is not a billable count.

Excisions by size and margin, biopsies, and Mohs

Excision codes (11400–11446 for benign, 11600–11646 for malignant) are selected by anatomic site and excised diameter including margins, not by the lesion size alone. Measure clinically before excision; pathology size does not replace the clinical measurement for CPT selection. Biopsy codes 11102–11107 distinguish tangential, punch, and incisional techniques with add-ons for additional lesions. Do not bill a biopsy when the intent and documentation support a full excision.

Mohs micrographic surgery uses 17311 for the first stage on head, neck, hands, feet, and genitalia (17313 for trunk/arms/legs), with 17312 / 17314 for additional stages. Each stage needs documented tissue maps and histopathologic examination by the surgeon. Repair codes may be separately billable when intermediate or complex repair is performed and not bundled by payer policy — check NCCI before stacking.

• Count lesions by type before picking 17000/17003/17004 vs benign destruction codes.
• Select excision CPTs using excised diameter including margins, by site.
• Use 11102–11107 only when the procedure is a biopsy, not a definitive excision.
• Keep cosmetic charges on self-pay tickets — never on the insurance claim with medical CPT codes.

Cosmetic vs medical: wall off the cash

Cosmetic services (elective destruction of benign lesions without medical necessity, aesthetic injectables, laser packages) should never ride an insurance claim "just to see if it pays." That habit creates false A/R, patient refunds, and compliance risk. Our dermatology medical billing workflows use separate ticket types and posting rules so cosmetic cash cannot contaminate medical ERA posting. Medical necessity diagnoses must match the procedure; "patient desires removal" is not a covered indication for most plans.

Pathology add-on timing matters when you hold claims for results. Bill the procedure when performed; bill professional pathology when the interpretation is complete. Holding the excision claim for two weeks "until path is back" ages A/R for no reason. A dermatology medical billing company should post both sides cleanly, keep first-pass rates at 97%+, and make sure malignant diagnoses update the chart without rewriting history on the original date of service. Days in A/R should stay under 28 even in a Mohs-heavy month.