4 Steps for Improved Excision Coding

Skin Excision Coding

Consideration of several factors, such as the type of removal, lesion size and location, pathologic results, intent, etc., is key to accurately coding dermatological lesion removal procedures. Let’s review the codes and guidelines for lesion removal by excision and how to avoid common mistakes when coding these skin procedures.

Excision – Benign/Malignant Lesions (11400-11646)

Excision involves the cutting and full-thickness removal of a lesion, with extension through the dermis into the subcutis. Skin lesion excisions include the surrounding tissue or margins. To accurately code lesion excisions, review the documentation for details regarding whether the lesion is benign or malignant, the location, and the excised diameter.

Skin excision coding may seem complex at first, but you can easily master it in four steps:

1. Check the Pathology Report

Skin excision codes are first classified based on information extracted from the pathology report on whether the lesion is benign (non-cancerous) or malignant (cancerous). Do not code the lesion type based on “suspected” or “probable.” Base your code selection on the pathology report, even if it means waiting a few days before submitting the claim.

If the report describes a benign lesion or one of uncertain behavior (for example, indications of atypia or dysplasia), assign a benign lesion code (11400-11446).

If pathology confirms malignancy, assign a malignant lesion code (11600-11646). Malignancies can be further classified into:

  • Carcinoma in-situ – precancerous cells that have not spread beyond the primary site; may evolve into an invasive malignancy
  • Primary site – the original, or first, tumor in the body growing at the anatomical site where tumor progression began
  • Secondary (metastatic) site – cancer cells that have spread from the primary site to other parts of the body and formed secondary tumors

Without a pathology report to confirm the diagnosis, you must assign an unspecified diagnosis and a benign lesion excision code (11400-11471).

2. Location Matters

Knowing whether the lesion was benign or malignant will help you select the code that also identifies the anatomic location from which the lesion was excised.

Benign Lesion

  • Trunk, arms, legs – 11400-11406
  • Scalp, neck, hands, feet, genitalia – 11420-11426
  • Face, ears, eyelids, nose, lips, mucous membrane – 11440-11446

Malignant Lesion

  • Trunk, arms, legs – 11600-11606
  • Scalp, neck, hands, feet, genitalia – 11620-11626
  • Face, ears, eyelids (skin only), nose, lips – 11640-11646

3. Calculate Excision Size

Code selection is determined by the size of the excision, not the size of the lesion. Excision size includes the size of the lesion plus the width of the excised margins (the area surrounding the lesion that is also removed). To calculate the excision size, measure the diameter of the lesion at its longest point (greatest clinical diameter) plus two times the narrowest margin appropriate for removing the entire lesion (the margin on both sides of the lesion).

Note: The rule of thumb is to measure first; cut second. The provider should measure the lesion and margins preoperatively because the lesion tissue generally changes shape or shrinks once removed and placed in formalin.

4. Consider the Circumstances

Before you code, make sure to evaluate for the presence of special circumstances such as removal of multiple lesions, re-excision, and bundling concerns.

  • Report each lesion separately; multiple excisions require a modifier. When the provider removes multiple lesions in a single visit, code each lesion separately, assigning specific CPT® and ICD-10-CM codes for every lesion treated, and report the most complex lesion first. Append modifier 59 Distinct procedural service to the second and all subsequent codes describing lesion excision in the same anatomic location.
  • Re-excision necessitates special consideration. The provider may revisit a previous excision to remove additional tissue if pathology shows malignancy in the margins. Proper reporting of this re-excision depends on the timing of the follow-up excision.

If re-excision is performed during the same session as the initial excision, report one code based on the final widest margin. This should describe the greatest area removed. For example, if the first excision measures 2.0 cm with margins, and the second excision increases the margins by 1.0 cm on all sides, code for a 4.0 cm excision. Do not report a 2.0 cm excision and a 4.0 cm excision.

If the re-excision is performed during a subsequent session, code based on the diameter of the new excision and append modifier 58 Staged or related procedure or service by the same physician during the postoperative period because the re-excision occurred during the global period of the initial excision.

  • Be on the lookout for bundling issues. According to CPT® guidelines, all lesion excision codes include local anesthesia and simple wound closure. Repair by intermediate or complex closure should be reported separately.

In such cases, report intermediate (12031-12057) and complex (13100-13153) repairs or reconstructive closure (15002-15261, 15570-15770) in addition to lesion excision (11440-11446). Note, however, payers who follow the National Correct Coding Initiative (NCCI) edits will bundle intermediate and complex repairs into excision of benign lesions of 0.5 cm or less (11400, 11420, and 11440).

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