Summary & Overview

CPT 11900: Intralesional Corticosteroid Injection for Large Nodules and Keloids

CPT code 11900 represents an intralesional corticosteroid injection used to treat large nodules, keloids, lichenified hyperkeratotic lesions, and similar localized dermatologic conditions. The code captures a commonly performed, procedure-based intervention in dermatology and surgical specialties that can reduce inflammation, scar tissue, and symptomatic lesion burden. Nationally, this code is relevant because it appears across outpatient dermatology clinics, ambulatory surgical centers, and office-based procedural settings, affecting coverage, documentation, and billing workflows.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication summarizes payer coverage patterns and common billing considerations for these organizations. Readers will find concise benchmarks on coding and site-of-service patterns, descriptions of typical clinical contexts in which the code is used, and notes on documentation elements that support medical necessity. Where specific payer policy details are not present in the input, the text indicates "Data not available in the input." The intent is to provide a national-level operational and clinical overview that supports coding accuracy and administrative planning without offering clinical recommendations.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare11900CPTintralesional injectioncorticosteroiddermatologykeloid treatmentprocedure codingoutpatient surgery

Billing Code Overview

CPT code 11900 describes an intralesional injection of a corticosteroid, commonly using agents such as triamcinolone acetonide. The procedure is indicated for treatment of large nodules, keloids, lichenified hyperkeratotic lesions, and other localized dermatologic conditions where direct corticosteroid delivery into the lesion is clinically appropriate.

Service type: Intralesional corticosteroid injection (procedure-based dermatologist or surgical dermatology service)

Typical site of service: Outpatient dermatology clinic, ambulatory surgical center, or office-based procedure room

Clinical & Coding Specifications

Clinical Context

A 34-year-old patient presents to a dermatology clinic with a firm, symptomatic keloid on the anterior chest that developed after piercings. The lesion is hyperpigmented, raised, and causing itching and cosmetic concern. After clinical evaluation and discussion of treatment options, the dermatologist elects to perform an intralesional corticosteroid injection using triamcinolone acetonide to reduce scar hypertrophy and inflammation. The workflow includes verifying informed consent, documenting lesion size and location, photographing the lesion, preparing medication and syringe, using aseptic technique to inject steroid directly into the lesion, observing the patient briefly for immediate adverse reaction, and providing post-procedure instructions and follow-up scheduling. Typical sites of service are outpatient dermatology clinics, ambulatory surgical centers, and office-based procedure rooms. The procedure is performed by dermatologists, plastic surgeons, or other qualified specialists with training in intralesional injections. The visit is coded with 11900 for intralesional injection of a corticosteroid for a single lesion; repeat injections at intervals may be billed per payer policy and documented in the medical record.

Coding Specifications

Modifier	Description	When to Use
`25`	Significant, separately identifiable evaluation and management service by the same physician on the same day of the procedure	Use when a distinct E/M visit is documented on the same day as `11900` (e.g., new problem visit leading to the injection).
`59`	Distinct procedural service	Use when `11900` is performed on a lesion distinct from another procedure on the same date that might be bundled.
`51`	Multiple procedures	Use when multiple different procedures are performed same day; payer rules may require modifier or quantity reporting.
`52`	Reduced services	Use when the service is partially reduced or not completed as described.
`76`	Repeat procedure by same physician	Use when the same physician repeats `11900` later the same day.
`77`	Repeat procedure by another physician	Use when another physician repeats the procedure the same day.
`50`	Bilateral procedure	Rare for single lesion injections; use if payer accepts bilateral reporting for symmetrical lesions treated same session.
`59`	Distinct procedural service	Used to indicate a distinct lesion treated when bundling edits might apply.
`24`	Unrelated E/M service during a postoperative period	Use when an unrelated visit occurs in the global period of a prior procedure.
`78`	Unplanned return to the OR/procedure for a related procedure during postoperative period	Use only if a return to a procedure room for a complication occurs.
`25`	Significant, separately identifiable E/M service on same day as procedure	See above; included because commonly applicable.
`GA`	Waiver of liability statement on file (no Medicare ABN)	Use when patient declines Medicare-covered service and ABN processes per payer.
`JW`	Drug or biological discarded/not administered to any patient	Use if medication is prepared but discarded; billing rules vary.
`LT`	Left side	Use for laterality reporting if applicable to payer requirements.

Taxonomy Code	Specialty	Notes
`207N00000X`	Dermatology	Most common specialty performing intralesional corticosteroid injections for keloids, nodules, and lichenified lesions.
`2084P0800X`	Plastic Surgery	Performs treatment for keloids and hypertrophic scars, often when surgical management is considered.
`207L00000X`	Allergy & Immunology	May perform intralesional injections for certain inflammatory lesions in select practices.
`207S00000X`	Family Medicine	Office-based intralesional injections for common skin lesions in primary care settings.
`207K00000X`	Internal Medicine	May perform injections in outpatient settings depending on provider scope and training.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`L91.0`	Hypertrophic scarring	Primary indication for intralesional corticosteroid injections to reduce scar tissue proliferation.
`L91.8`	Other hypertrophic disorders of skin	Includes related scar disorders treated with intralesional steroids.
`L91.9`	Hypertrophic disorder of skin, unspecified	Used when specific scar type is not further specified.
`L50.9`	Urticaria, unspecified	Occasionally intralesional steroids used for localized inflammatory nodules; limited indications.
`L28.0`	Lichen simplex chronicus	Intralesional steroids may be used for refractory, lichenified hyperkeratotic plaques.
`L73.2`	Keloid scar	Classic indication for `11900` to reduce keloid size and symptoms.
`L98.9`	Disorder of skin and subcutaneous tissue, unspecified	Used when a specific diagnosis is not documented but lesion treated with intralesional steroid.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`11901`	Injection, intralesional; second and each additional lesion (List separately in addition to code for primary procedure)	Billed when more than one lesion is treated during the same session in addition to `11900` for the first lesion.
`12001`	Simple repair of superficial wounds of face, ears, eyelids, nose, lips; 2.5 cm or less	May be performed when surgical excision or repair is required for scar revision in conjunction with intralesional therapy in the same episode of care.
`12032`	Layer closure of wounds, face; 2.6 cm to 7.5 cm	Related when scar revision with more complex closure follows or precedes steroid injections.
`17000`	Destruction (e.g., laser), premalignant lesions; first lesion	Alternative or adjunct procedures for certain epidermal lesions; may be performed in the same treatment plan.
`99213`	Office or other outpatient visit for established patient, moderate complexity	Common E/M code for pre- or post-procedure visit when a separate evaluation is documented on the same day as `11900`.