Dermatology Billing Services / Audit Brief 2026

Mohs in 2026: the single number that decides whether your claim survives audit

It is not the diagnosis. It is not the payer. It is your stage count, and whether one surgeon read the slides. Get those two right and the rest is arithmetic.

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number that drives the whole claim: stages
The answer, up front

Mohs reimbursement is built one stage at a time. You bill the first stage once (17311 or 17313), then every additional stage as an add-on (17312 or 17314), then extra tissue blocks beyond five per stage (17315). The number of stages your documentation supports is the number that gets paid, and it is the first number an auditor recounts against your maps and slides.

The second trip-wire is the same-surgeon pathology rule. The Mohs codes only exist because one physician acts as both the surgeon and the pathologist on the same day. Send the tissue to a separate pathologist and you have not done Mohs, you have done an excision plus a path read, and the codes change completely. Bill a separate pathology or frozen-section code on that same specimen and NCCI bundles it right back out.

Everything below is how those two numbers behave under the CMS CY2026 Physician Fee Schedule and current NCCI edits.

CPT 17311 to 17315 / how stages stack

The stage ladder is the reimbursement engine

Payment climbs with each documented stage and each extra block, not with the size of the lesion or the payer on the card. Read the ladder the way an auditor reads your operative note: one countable step at a time.

17311First stage

Head, neck, hands, feet, genitalia. First stage, up to 5 tissue blocks. Billed once per site, per session.

base stage value
17312+ each stage

Add-on to 17311. Each additional stage, up to 5 blocks. Report per stage actually taken and mapped.

stacks with every stage 2, 3, 4...
17313First stage

Trunk, arms, legs. First stage, up to 5 tissue blocks. The anatomic twin of 17311, different site family, never both on the same lesion.

base stage value
17314+ each stage

Add-on to 17313. Each additional trunk/extremity stage, up to 5 blocks.

stacks with every stage 2, 3, 4...
17315+ each block

Add-on, any stage. Each additional tissue block beyond the first five in any single stage. This is where high-block cases quietly earn or quietly leak.

per block over 5, per stage
The same-surgeon rule / one fork, two outcomes

One physician, both roles, or it is not Mohs

The Mohs family assumes the operating physician personally acts as pathologist and reads the frozen sections during the same session. That single fact decides which codes you are even allowed to open.

Path A / bill Mohs

Surgeon reads the slides

Same physician excises, maps, and personally interprets the frozen sections in one session. This is the entire premise of 17311 to 17315.

then, correct: 17311/17313 + 17312/17314 per stage + 17315 per extra block
Path B / not Mohs

Tissue goes to a separate pathologist

A different provider reads the specimen. The Mohs premise is broken. Report the excision and the separate pathology under their own codes, never the Mohs set.

then, correct: excision + separate path read, not 17311 to 17315
NCCI edits / same-day path and repair

What NCCI bundles into the Mohs stage, and what it does not

The Mohs codes already pay for the surgeon acting as pathologist and for simple wound handling. NCCI Procedure-to-Procedure edits enforce it. Know which lines are baked in and which survive with documentation and the right modifier.

Same-day service on the Mohs specimenStatusWhy
Surgical pathology on the Mohs tissue (88302 to 88309)BundledThe path read is the reason Mohs codes pay more. Reporting it separately double-counts the same work.
Frozen section pathology (88331/88332) on the same specimenBundledIntraoperative slide reading is intrinsic to each Mohs stage. Not separately payable by the same surgeon.
Simple repair of the Mohs defectBundledBasic wound closure is included in the stage value.
Intermediate / complex repair (12031 to 13160)SeparableDistinct, documented layered or complex closure may be reported, with the payer-appropriate modifier and its own note.
Adjacent tissue transfer, flap or graft reconstructionSeparableA separately identifiable reconstruction is its own procedure when the operative detail supports it.
Diagnostic biopsy of a different lesion, same daySeparableA distinct lesion, distinct site, supported by a modifier that documents the separate service, not a default 59.

An edit existing does not prove both services are billable. A bypass modifier is a documentation claim, not a shortcut, and it has to be true on the complete claim.

Where the number leaks

Three counts an auditor recounts first

StagesEvery 17312/17314 must map to a numbered stage with its own drawing and slide. No map, no add-on stage.
Blocks17315 only lives above five blocks in a single stage. Miscount and you either under-bill the case or invite a takeback.
ReadersOne physician on the pathology, or the Mohs codes do not apply. This is the fastest edit a reviewer can flag.
MIPS 2026 / the quality side of the claim

Clean stage counts feed clean quality reporting

Under the CY2026 Quality Payment Program, dermatology practices reporting through MIPS and the dermatology-relevant MVP carry measures that lean on the same documentation discipline your Mohs claims already need.

Melanoma: Continuity of CareRecall-system and coordination measures reward the same tracked follow-up that supports Mohs medical necessity.
Biopsy Reporting TimeTurnaround measures depend on the specimen and path documentation your Mohs workflow produces.
Dermatology MVPThe specialty MVP bundles quality, cost and improvement activities, so accurate coding and quality reporting move together.
Cited by name
2026 guidance this brief is built on
  • CMS CY2026 Medicare Physician Fee Schedule Final Rule. Sets the conversion factor and relative value inputs that price each Mohs stage and add-on.
  • CPT codes 17311, 17312, 17313, 17314, 17315 (AMA CPT 2026). The Mohs micrographic surgery family, first-stage, additional-stage, and additional-block structure.
  • National Correct Coding Initiative (NCCI) Procedure-to-Procedure edits and Policy Manual, 2026. Bundling of same-day surgical and frozen-section pathology and simple repair into the Mohs stage.
  • CMS Quality Payment Program, MIPS and the dermatology MVP for the 2026 performance year. Quality measures for melanoma continuity of care and biopsy reporting.

Recount your Mohs claims before an auditor does

ASP-RCM builds dermatology billing around the two numbers that decide the claim: the stage count and the same-surgeon pathology check. We reconcile every 17312 and 17314 to a documented stage, catch 17315 blocks that quietly leak, and hold NCCI bundling and modifiers to what the note actually supports, so your claims survive the recount.

Talk to our dermatology billing team

This brief is coding guidance, not legal or payer-specific advice. Verify against your current CMS CY2026 PFS, NCCI edition, and payer policy.