Summary & Overview
HCPCS L5655: Below-Knee Prosthetic Socket Insert
HCPCS Level II code L5655 denotes a prosthetic accessory: an addition to a below-knee (transtibial) prosthetic socket using materials such as kemblo, pelite, aliplast, or plastazote. This code identifies a component intended to improve socket fit, pressure distribution, and user comfort—an important element of prosthetic care that affects mobility and quality of life for amputees across the country. Nationally, accurate coding of prosthetic socket components supports appropriate device provision, claims adjudication, and patient access to necessary fittings and adjustments.
Key payers covered in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of what L5655 represents, where the service is typically delivered, and the clinical context for its use. The report also provides benchmarks and payer coverage notes where available, policy updates affecting prosthetic component coding, and billing considerations for outpatient prosthetics providers and durable medical equipment suppliers.
This publication is intended for billing professionals, prosthetists, compliance officers, and policy analysts seeking a practical reference for the code’s clinical role, common sites of service, and the payer landscape relevant to prosthetic socket additions. Data not available in the input will be noted where applicable.
Billing Code Overview
HCPCS Level II code L5655 describes an addition to a below-knee lower extremity prosthetic socket made from materials such as kemblo, pelite, aliplast, plastazote, or equivalent. This component is an accessory intended to be inserted into a transtibial (below-knee) socket to improve fit, comfort, or suspension for the prosthesis wearer.
Service type: Prosthetic socket insert/addition for lower extremity
Typical site of service: Outpatient prosthetics or orthotics clinic, prosthetist’s office, or durable medical equipment provider setting
Clinical & Coding Specifications
Clinical Context
A 62-year-old male with a transtibial (below-knee) amputation presents for routine prosthetic socket maintenance and comfort optimization. The patient reports increased distal pressure points, mild skin irritation, and progressive volume changes of the residual limb after recent weight fluctuation. The prosthetist evaluates the socket fit in the clinic, determines that a soft socket insert (materials such as kemblo, pelite, aliplast, plastazote or equivalent) is required to improve load distribution and reduce shear. The workflow includes a focused history and residual limb inspection, socket trial with a new insert, any necessary trimming or shaping of the insert, and final fitting verification. The service is coded using L5655 for the addition of a below-knee socket insert. Typical sites of service are outpatient prosthetics clinics, orthotics and prosthetics (O&P) offices, or hospital-based prosthetics departments. The patient encounter may follow prior prosthetic fabrication or routine follow-up visits and can occur on the same day as socket adjustments or component repairs. Documentation should include residual limb assessment, reason for insert addition, description of material used, time spent, and confirmation of patient tolerance and fit.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
LT | Left side | When the prosthesis or insert is for the left lower extremity |