11400

Excision, benign lesion including margins, except skin tag (unless listed elsewhere), trunk, arms or legs; excised diameter 0.5 cm or less

CPT code 11400 describes the surgical excision of a benign skin lesion located on the trunk, arms, or legs, with an excised diameter of 0.5 cm or less, including margins. This procedure is indicated for patients presenting with benign dermatological conditions such as nevi (moles), cysts, fibromas, or lipomas that require removal due to symptomatology, rapid changes in size or color, persistent irritation, or suspected malignant potential where a full excision is diagnostically preferred over a biopsy. The excision process involves the full-thickness removal of the lesion down to, or through, the dermis. The physician first measures the lesion plus the required margins at their widest clinical diameter to determine the correct CPT code. After obtaining informed consent, the designated area is prepped and draped in a sterile fashion. Local anesthesia, typically a lidocaine injection with or without epinephrine, is administered to numb the surgical site. Using a scalpel, the physician makes an elliptical incision around the lesion encompassing the appropriate margins. The tissue is carefully dissected and completely removed from the underlying subcutaneous layer. Hemostasis is achieved using electrocautery or chemical agents if necessary. The resulting defect is then closed using simple repair techniques (e.g., single-layer closure with sutures, staples, or tissue adhesives), which are inherently included in the excision code and should not be billed separately unless an intermediate or complex closure is medically necessary and documented. The excised specimen is typically placed in formalin and sent to a dermatopathology laboratory for histopathological examination to definitively confirm its benign nature and ensure clear surgical margins. Post-operative care instructions are provided to the patient emphasizing wound care, infection prevention, and scheduled suture removal. Correct coding relies strictly on the excised diameter (lesion plus margins) measured prior to excision, not the size of the histological specimen post-shrinkage.

Clinical Indications

  • Symptomatic benign nevus on the arm, trunk, or leg.
  • Epidermoid cyst measuring less than 0.5 cm causing pain or irritation.
  • Atypical mole requiring complete excision to rule out malignancy.
  • Dermatofibroma on the leg subjected to repeated trauma from shaving or clothing.

Procedure Steps

  1. Measure the lesion and the planned surgical margins to determine the excised diameter.
  2. Cleanse and prep the surgical site on the trunk, arm, or leg.
  3. Administer local anesthetic to the area surrounding the lesion.
  4. Perform an elliptical incision through the dermis to encompass the lesion and margins.
  5. Dissect the lesion free from the underlying subcutaneous tissue.
  6. Achieve hemostasis using pressure, chemical cautery, or electrocautery.
  7. Perform simple closure of the surgical defect using sutures.
  8. Apply a sterile dressing to the wound.
  9. Send the excised tissue specimen to pathology for histopathological analysis.

Coding Guidelines

  • The excised diameter is determined by measuring the widest clinical diameter of the lesion plus the most narrow margins required for complete excision (lesion diameter plus two times the margin).
  • Do not report simple closure (12001-12021) separately as it is included in the excision code.
  • If intermediate (12031-12057) or complex (13100-13153) closure is required and performed, it may be reported separately.
  • Measurement must be taken prior to excision, as tissue shrinks post-removal and in formalin.
  • If the pathology report indicates the lesion was malignant, use the malignant excision codes (11600-11646) instead, provided the pathology report is available before claim submission.
  • Do not use this code for skin tag removal (11200, 11201).

Associated ICD-10 Codes