Summary & Overview

CPT 11603: Excision of Malignant Skin Lesion, Trunk/Arms/Legs 2.1–3.0 cm

CPT code 11603 denotes the excision of a malignant skin lesion, including margins, with a lesion diameter of 2.1 to 3.0 cm from the trunk, arms, or legs. This code captures a common dermatologic and surgical oncology procedure used to treat invasive skin cancers and is important for reimbursement, quality reporting, and procedural tracking across ambulatory and hospital outpatient settings. Nationally, accurate coding for lesion size and anatomic site is critical to ensure appropriate payment and to support clinical registry and surveillance activities.

Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, United Healthcare, and Medicare. The publication provides a concise review of code definition and clinical context, payer coverage considerations, common billing modifiers and associated provider taxonomies, mapping to representative ICD-10 diagnoses, and closely related CPT codes used for smaller lesion sizes. Readers will find benchmarks and policy-relevant notes that clarify typical use cases, compare 11603 to adjacent codes 11602 and 11600, and summarize documentation elements that influence coding selection. The material is presented for a national audience to support coding accuracy, claims processing, and clinical documentation alignment for oncologic skin excisions.

AetnaBlue Cross Blue ShieldCigna HealthUnited HealthcareMedicare11603CPTskin excisiondermatologic surgerymalignant lesionoutpatient surgeryprocedure codingsurgical oncology

Billing Code Overview

CPT code 11603 describes the surgical excision of a malignant skin lesion, including margins, with a lesion diameter of 2.1 to 3.0 cm. The procedure is performed on the skin of the trunk, arms, or legs and involves removal of the cancerous tissue to achieve appropriate oncologic margins.

Service Type: Surgical excision of malignant cutaneous lesion

Typical Site of Service: Outpatient surgical setting, ambulatory surgery center, or hospital outpatient department (skin of trunk, arms, or legs)

Clinical & Coding Specifications

Clinical Context

A 62-year-old male presents to the dermatology clinic with a biopsy-confirmed malignant melanoma on the right posterior arm measuring approximately 2.5 cm in greatest diameter. The lesion was diagnosed after an excisional biopsy that returned positive for invasive melanoma requiring wider surgical margins. The patient has controlled hypertension and no active anticoagulation. Preoperative evaluation includes history and focused physical exam, review of pathology, marking of surgical margins in clinic, informed consent, and discussion of expected wound closure (primary closure vs. flap/graft). On the day of service the patient is placed under local anesthesia with possible monitored anesthesia care depending on patient comfort and comorbidities.

The provider performs a wide local excision of the malignant lesion including clinically appropriate margins, with total excised diameter in the range of 2.1 to 3.0 cm on the arm. Hemostasis is achieved, and the wound is closed with layered sutures. Specimens are submitted for permanent pathology. Postoperative instructions and wound care are documented and an outpatient follow-up visit is scheduled for suture removal and pathology review. Typical sites of service include an outpatient dermatology clinic procedure room, ambulatory surgical center, or hospital outpatient department.

Coding Specifications

Modifier	Description	When to Use
`25`	Significant, separately identifiable evaluation and management service on the same day as a procedure	Use when a distinct E/M is performed and documented on the same day as the excision (e.g., new problem evaluation leading to the procedure).
`26`	Professional component	Use when only the professional component of a service is reported separately (rare for excision CPT).
`50`	Bilateral procedure	Use when the same excision procedure is performed bilaterally (rare for trunk/arms/legs but applicable if mirrored lesions).
`51`	Multiple procedures	Use when multiple distinct CPT-coded procedures are performed during the same operative session in addition to the excision.
`52`	Reduced services	Use when the excision is partially reduced or not completed as originally planned.
`53`	Discontinued procedure	Use when the procedure is started but discontinued due to unforeseen clinical circumstances.
`59`	Distinct procedural service	Use to indicate a separate and distinct procedure not normally reported together, when appropriate and supported by documentation.
`62`	Two surgeons	Use when two surgeons work together as co-surgeons performing distinct portions of the excision/closure.
`76`	Repeat procedure by same physician	Use when the physician repeats the procedure within the global period for a related reason and documentation supports repeat.
`78`	Unplanned return to the operating/procedure room by the same physician following initial procedure for a related procedure during the global period	Use when the patient returns to OR/procedure room for a complication necessitating further surgery during the global period.
`79`	Unrelated procedure or service by the same physician during the postoperative period	Use when an unrelated procedure is performed during the global period.
`GA`	Waiver of liability statement on file (Medicare)	Use when a Advance Beneficiary Notice/waiver is on file and required for coverage determination.
`LT`	Left side	Use to designate the left-sided anatomic location for laterality reporting.
`RT`	Right side	Use to designate the right-sided anatomic location for laterality reporting.

Taxonomy Code	Specialty	Notes
`207N00000X`	Dermatology Physician	Commonly performs excisions of malignant skin lesions on trunk, arms, and legs.
`207ND0101X`	MOHS-Micrographic Surgery Physician	Specializes in micrographic surgery; may perform surgical excisions when MOHS is not indicated or in combined workflows.
`208600000X`	Surgery Physician	General or surgical specialists who perform wide local excisions and more complex closures in ambulatory surgical settings.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C43.0`	Malignant melanoma of scalp and neck	Malignant melanoma diagnosis that may require excision; anatomic location guides procedural site selection and documentation.
`C43.11`	Malignant melanoma of right ear and external auricular canal	Malignant melanoma on external ear structures; excision code selection depends on anatomic site—this CPT describes trunk/arms/legs so this diagnosis may require a more site-specific CPT if on ear.
`D03.0`	Melanoma in situ of lip	Non-invasive melanoma in situ; excision may require different margins and coding considerations but is clinically related as a spectrum of melanoma diagnoses.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`11600`	Excision, malignant lesion including margins, trunk, arms, or legs; lesion diameter 0.5 cm or less	Represents the smaller size tier for malignant lesion excision; used when lesion diameter is ≤ 0.5 cm instead of `11603`.
`11602`	Excision, malignant lesion including margins, trunk, arms, or legs; lesion diameter 1.1 to 2.0 cm	Represents the adjacent smaller size tier; used when lesion diameter is 1.1–2.0 cm instead of `11603`.