15.1 Integumentary Surgery

15.1 Integumentary Surgery

Quick Answer: Hospital outpatient and ambulatory surgical center (ASC) integumentary coding is a decision tree: benign versus malignant excision families (11400–11446 versus 11600–11646), excised diameter (lesion plus margins), site group, then whether closure is included simple repair, separately reportable intermediate (12031–12057) or complex (13100–13153) repair, adjacent tissue transfer (ATT) (14000–14302), graft, or flap. For calendar year (CY) 2026, Current Procedural Terminology (CPT) application codes 15271–15278 still describe skin-substitute application; the product is unpackaged from those application Ambulatory Payment Classifications (APCs) under the Centers for Medicare & Medicaid Services (CMS) Outpatient Prospective Payment System (OPPS) final rule CMS-1834-FC.

This independent OpenExamPrep chapter helps learners study facility integumentary, musculoskeletal, and respiratory surgery coding for the American Academy of Professional Coders (AAPC) Certified Outpatient Coder (COC) exam. It is not an AAPC, CMS, or American Medical Association (AMA) product, and OpenExamPrep does not claim partnership, official review, or approval by those organizations.

Why integumentary items sit in Surgery and modifiers

AAPC's Taking the COC exam page assigns 22 of 100 questions to surgery and modifiers and limits that domain to procedures approved for outpatient hospital and ASC facilities. Lesion destruction, excision, repair, breast same-day surgery, nail work, debridement, and wound-product application are everyday same-day surgery (SDS) and ASC cases. Facility reporting does not use a professional global surgical package to swallow postoperative visits, but it still uses CPT parentheticals, National Correct Coding Initiative (NCCI) procedure-to-procedure (PTP) edits, and OPPS packaging. A coder who picks a 114xx code from a pathology ruler after a 2.0 cm excision with margins, or who still bills deleted C5271–C5278 application codes in 2026, misses the item.

Use representative family numbers in this chapter as decision labels. Open the current CPT Professional book for the indented code that matches site and size; do not paste long proprietary descriptors into notes or flash cards.

Lesion excision: malignancy, site, and the ruler that counts

Excision of a cutaneous lesion is reported from 11400–11446 when the known or suspected pathology driving the procedure is benign, and from 11600–11646 when it is malignant (including melanoma and other cutaneous malignancies the surgeon is treating as cancer). The pathology report can confirm what you already coded from the operative intent; it is not a license to recode size after the specimen shrinks in formalin.

Three facts select the code:

1. Benign versus malignant family
2. Anatomic site group (trunk and extremities versus scalp, neck, hands, feet, and genitalia versus face, ears, eyelids, nose, lips, and mucous membrane)
3. Excised diameter, not the lesion alone

CPT's measurement rule is clinical, not histologic. Add the lesion's greatest clinical diameter to twice the narrowest margin taken (a margin on each side of that diameter). A 1.0 cm lesion excised with 0.5 cm margins is a 2.0 cm excision. A 0.8 cm malignant cheek lesion with 0.4 cm narrowest margins is 1.6 cm, which is a different 116xx row than 0.8 cm. Measure before the ellipse is distorted. If the note states planned margins and the excised diameter, do not override them with a smaller pathology measurement.

Each discrete lesion is coded unless an NCCI edit or a reconstruction rule bundles it. Do not add two excision codes for one ellipse that removes one lesion.

Intermediate versus complex repair

Simple repair is one-layer closure of the skin and is bundled into excision. Intermediate repair is layered closure of deeper subcutaneous tissue or fascia (single-layer skin closure plus deeper sutures), or single-layer closure of a heavily contaminated wound that required extensive cleaning or removal of particulate matter. Complex repair is more than layered closure: scar revision, debridement of traumatic wounds that are already infected or heavily contaminated beyond intermediate work, stents, retention sutures, or extensive undermining and advancement that still is not ATT.

Repair length is added among repairs that share the same classification and the same CPT anatomic grouping. Add two intermediate trunk repairs; do not add an arm intermediate length to a face complex length and pick one code. Traumatic laceration repairs use the same families when no lesion was excised. When a lesion is excised and the defect needs intermediate or complex repair, report both the excision and the repair. When ATT, a flap, or a graft closes the defect, the reconstruction family replaces a separately reported repair of that same defect.

Adjacent tissue transfer versus graft versus flap

ATT (14000–14302, plus the 14350 family when applicable) describes transferring or rearranging adjacent tissue—Z-plasty, W-plasty, V-Y, rotation, or advancement from tissue next to the defect. Code selection uses defect size (primary defect plus secondary defect created by the transfer) and site. CPT includes excision of the lesion in ATT. Reporting 116xx plus 140xx for one malignant lesion closed by a rotation flap from adjacent skin is unbundling.

Skin grafts use a distant donor site. Split-thickness grafts live in the 15100 family; full-thickness grafts live in the 15200 family. Select by recipient site and sq cm. Donor-site closure is separately reportable only when CPT and NCCI allow it and the closure is more than the simple work already contemplated. Flaps in the 15570–15738 range and named muscle or myocutaneous families require a described vascular pedicle or muscle unit. "Wide undermining" without a pedicle is repair or ATT, not a named flap.

Destruction (17000–17004 for premalignant lesions; 17110–17111 for many other benign lesions) is selected by documented method (cryosurgery, electrosurgery, laser, chemical) and by lesion count. Do not report destruction and excision of the same lesion. Nail procedures use 11720–11721 (debridement), 11730 (plate avulsion), 11750 (excision of nail and matrix), and 11755 (biopsy). Name the digit and laterality (LT/RT).

Debridement depth

The word "debrided" does not pick the code. Selective debridement of epidermis or dermis uses 97597–97598. Surgical debridement is coded by depth and surface area: subcutaneous tissue 11042 (add-on 11045), muscle or fascia 11043 (add-on 11046), bone 11044 (add-on 11047). Do not report debridement of tissue that is the excised specimen, the ATT, or the graft bed in a way that duplicates the same square centimeters. If the surgeon documents subcutaneous debridement of a 25 sq cm ulcer and no excision, 11042 plus 11045 is the family path—not a skin-substitute application code unless a product is also applied.

Outpatient breast biopsy and mastectomy

Percutaneous image-guided breast biopsy uses 19081–19086 by modality (stereotactic, ultrasound, magnetic resonance) with an add-on for additional lesions on the same breast. Open biopsy and lumpectomy-type excisions use 19100, 19101, 19120, and 19125 when those are the documented approaches. Localization device codes in the 19281–19288 range apply when that work is not already included in the biopsy family performed.

Partial mastectomy 19301 and 19302 (with axillary lymphadenectomy) are common SDS codes. Simple mastectomy 19303 may appear in the outpatient hospital or ASC when the case is clinically appropriate for that setting. Code the procedure performed, including sentinel-node sampling when it is a distinct documented service and not already described by a combination code. Do not code a planned 19303 if the surgeon stopped at 19301. Laterality modifiers belong on paired breasts.

Skin substitute products in CY 2026 — application stays; product coding changed

CPT 15271–15278 still describe application of a skin substitute, chosen by anatomic site (trunk, arms, legs versus face, scalp, eyelids, mouth, neck, ears, orbits, genitalia, hands, feet, and multiple digits) and by wound surface area, with add-on codes for each additional 25 sq cm. CMS's CY 2026 OPPS/ASC final rule (CMS-1834-FC, November 21, 2025) and the January 2026 OPPS update (MM14361 / CR 14361) unpackaged sheet-form products from those application services. Products are paid separately as incident-to supplies, grouped by Food and Drug Administration (FDA) pathway into APC 6000 (premarket approval, PMA), APC 6001 (510(k)), and APC 6002 (section 361 human cells, tissues, and cellular and tissue-based products, HCT/P), with new status indicator S1. CMS published a uniform initial rate of $127.14 per cm² across those three APCs and created unlisted product codes Q4431–Q4433. Section 351 licensed biologics stay on the biological payment path. Non-sheet forms remain packaged with a separately payable service for CY 2026.

Effective December 31, 2025, CMS deleted low-cost application Healthcare Common Procedure Coding System (HCPCS) codes C5271–C5278. In the hospital outpatient department, add-on application CPT codes 15272, 15274, 15276, and 15278 remain packaged. The COC decision rule is narrow: still report 15271–15278 for the application; report the product with the characteristic HCPCS mapped to APC 6000–6002; do not resurrect deleted C-codes.

NCCI: separate procedure and same-incision approach

A CPT separate procedure is payable when it is the only procedure in that region and session. It is not payable when it is the approach to, or an integral inspection during, a more extensive integumentary service. Work done through the same incision or wound—exploration, hemostasis, simple closure, routine undermining—is not a second surgery. Modifier 59 or XE/XP/XS/XU (CMS MLN1783722, April 2026) is for a truly distinct lesion, site, or session, not for "I want both codes."

Mini-op-note (hospital SDS)

Pre-op diagnosis: suspected melanoma, left forearm. Measurement in the holding area: lesion 1.2 cm; planned 0.5 cm margins (excised diameter 2.2 cm). Procedure: elliptical excision into subcutaneous fat; frozen section confirms malignancy with clear margins; layered intermediate repair 4.5 cm. No graft, no ATT. Facility coding: malignant excision family 11600–11606 by 2.2 cm on trunk/arm/leg, plus intermediate repair 12031–12037 for 4.5 cm. Do not add ATT. Do not recode from a 1.2 cm pathology measurement. Append LT when the payer requires laterality on the arm.