Skin biopsy, destruction and lesion excision

Where you are

Skin procedure coding begins with a precise description of what happened to each lesion. The word “removed” is not enough. You need the site, technique, purpose, measurements and relationship to any other work. Keep your authorized CPT book open at the integumentary section.

A lesion is a localized abnormal area. A specimen is tissue sent for examination. They are related, but they are not interchangeable counting units. One removal can contain several lesions, and several needle passes can sample one lesion. This lesson helps you build the record before selecting the entry.

Make a lesion map

Give each documented lesion its own row in your worksheet. Record the anatomical location and laterality, the clinician's description, what was done and which specimen label belongs to it. Do not combine two nearby lesions merely because they share an arm or a pathology container.

Original fictional encounter: the clinician excises a lesion on the left upper arm, samples a separate lesion on the right shoulder and freezes another lesion on the back. Three distinct locations and three actions need review. A summary reading “skin lesions treated” loses the facts that explain separate services.

The map also prevents a more serious error: reporting a biopsy and removal as though they concerned different lesions when they actually concerned the same one. Medicare NCCI distinguishes same-lesion tissue sampling from a biopsy of a different lesion. [ncci-integumentary-2026, E.1–2]

Identify the completed technique

Removal methods include destruction, shaving, excision, debridement and other defined services. Read what the clinician actually performed rather than selecting the first Index entry under “removal.” NCCI allows one removal procedure for a lesion; starting with one method and converting to another does not ordinarily create two completed removals. [ncci-integumentary-2026, E.1]

In an original fictional note, a clinician starts one removal method, decides it is inadequate and completes removal through a different method. Your worksheet should preserve the conversion, but the reporting investigation follows the completed procedure. It should not multiply services merely because the report contains two technique names.

Use the full current entry to check whether selection depends on number, size, location, lesion type or another feature. Those variables differ across families. Never carry a size rule from one family into another without reading the instruction.

Biopsy is not a label for every specimen

A specimen sent to pathology does not by itself prove a separately reportable biopsy. Tissue may have been obtained during definitive removal. For the same lesion at the same encounter, NCCI includes the biopsy in lesion removal. A biopsy of a different lesion may be separately reportable when the complete rules are met. [ncci-integumentary-2026, E.2]

Compare two fictional records. In the first, a small sample is taken from the left-arm lesion and that same lesion is removed during the encounter. In the second, the left-arm lesion is removed and a separate right-shoulder lesion is biopsied. The difference is the lesion relationship, not whether both samples have laboratory labels.

For a biopsy-only service, record the actual sampling method and depth. Locate its primary and additional-lesion instructions in the authorized book. Do not use the number of instruments, stitches or specimen fragments as a substitute for the specified unit.

Measure an excision before removal

The WPS local Medicare policy describes excision measurement using the lesion's greatest clinical diameter and the narrowest necessary margins, recorded before excision. This measurement is distinct from the eventual closure length. The policy applies to its listed jurisdictions, including Michigan; other payer coverage still requires separate review. [skin-lcd-wps, Coverage Guidance]

Original fictional measurement: the largest visible diameter is 1.4 cm and the documented narrowest margin is 0.2 cm on each side. The excised diameter for this exercise is 1.4 + 0.2 + 0.2 = 1.8 cm. A later 3.1 cm closure does not replace that diameter.

Show the units in your calculation. If the same measurements are 14 mm and 2 mm per side, the total is 18 mm, or 1.8 cm. Do not enter 18 into a centimeter range. Nor should you infer a missing margin from the final wound length. Seek clarification if the required pre-excision measurement is absent.

Keep diagnosis and procedure evidence together

The procedure note explains the work. The diagnostic record and any pathology report explain what the lesion is. Reconcile those records before selecting an entry whose family depends on the lesion type. A coder should not decide that a lesion is malignant from its appearance alone.

For a fictional lesion initially described as suspicious, the final report later establishes a benign diagnosis. Do not preserve an assumed malignant conclusion simply because it appeared on the schedule. Conversely, do not treat the absence of a final report as proof of benign behavior. Identify the unresolved fact and complete the documentation review.

A separate pathology service has its own specimen rules. Under NCCI, multiple lesions submitted as one specimen do not automatically justify a separate pathology unit for every lesion. The reason for separate, precisely identified specimens matters. [ncci-integumentary-2026, E.4]

Drainage, anesthetic and cleanup

Incision or drainage needed to complete another procedure at the same site and encounter is included under the cited NCCI rule. Necessary debridement around the lesion to complete removal is also included. Local anesthetic administered by the procedural clinician is not transformed into a separate therapeutic injection. [ncci-integumentary-2026, C,D,E.7]

These are relationship checks. An independently treated condition at a different site needs its own review, but “separate paragraph” and “separate instrument” are not evidence of a separately reportable service. Read the operative purpose of each step.

Mohs has a combined professional role

Mohs involves the same physician performing the surgical removal and the microscopic examination. NCCI includes the ordinary excision and associated pathology work in that service. A diagnostic biopsy needed to establish the diagnosis before proceeding can have a different reporting relationship, subject to the specific requirements. [ncci-integumentary-2026, F]

Do not label every margin-controlled excision “Mohs.” Identify who performed each part and what the report establishes. Then verify stages, tissue blocks, site and any repair through the current book. The presence of a pathologist's report elsewhere in the chart does not settle the surgeon's service.

Book drill

Use the three-lesion map to find each procedure family. For the 1.8 cm excision, locate the correct site group and size interval without using the closure length. Read the same-lesion biopsy instruction and the Mohs section. Record the page and the exact fact that changed your selection.

Checkpoint

Explain why a specimen is not always a separately reportable biopsy, why two attempted techniques do not mean two removals, and why an excision diameter differs from a closure length. Identify the missing facts you would clarify before final coding.

Compare the key distinctions

Track each lesion, preserve the completed technique and measure with the correct units. Check included services before adding another procedure. Use the clinical and pathology documentation together; do not infer a diagnosis or a missing margin.

Sources

1. CMS — Medicare NCCI 2026 Chapter III: Integumentary System. 2026. Accessed 2026-09-10.
2. WPS Medicare / CMS Medicare Coverage Database — LCD L35498: Removal of Benign Skin Lesions. Revision effective October 30, 2025; currently in effect. Accessed 2026-09-10.