Summary & Overview
HCPCS L5644: Addition to Lower Extremity, Above-Knee, Wood Socket
HCPCS Level II code L5644 represents the addition of a wood socket to an above-knee (transfemoral) lower-extremity prosthesis. This prosthetic component code is relevant to prosthetists, durable medical equipment suppliers, and payers because it specifies a distinct fabrication or modification service that can affect device functionality, patient fit, and benefit coverage decisions. Nationally, accurate coding for prosthetic additions like L5644 matters for clinical continuity, claims adjudication, and standardized payment across settings.
Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the code’s clinical context and typical settings of service, plus information about common modifiers and payer considerations when available. The publication also outlines benchmarks and policy-relevant notes where present, as well as practical billing and documentation elements tied to prosthetic additions.
The summary provides a concise reference for coding staff, prosthetic providers, and billing auditors seeking clarity on the role of L5644 in claims, coverage pathways, and clinical descriptions of above-knee prosthetic modifications. Data not available in the input is noted where applicable.
Billing Code Overview
HCPCS Level II code L5644 denotes an addition to a lower extremity prosthesis, above-knee, wood socket. This code describes a component used to modify or augment an existing above-knee prosthetic device by adding a wood socket portion to the lower-extremity prosthesis.
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Service Type: Prosthetic component installation or modification for an above-knee (transfemoral) prosthesis
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Typical Site of Service: Orthotics and prosthetics clinic; prosthetic fabrication lab; outpatient prosthetics service
Clinical & Coding Specifications
Clinical Context
A 68-year-old male with a transtibial to transfemoral amputation revision presents to a prosthetics clinic for modification of a prefabricated above-knee wooden socket. The patient reports increased distal femoral pressure and decreased prosthetic comfort after weight gain and residual limb volume changes. The certified prosthetist performs an in‑clinic assessment, casts the residual limb (or uses a digital scan), and fabricates an addition to the existing above-knee wooden socket to relieve pressure, improve fit, and restore functional gait. The workflow includes clinical evaluation, measurement, fabrication of the addition component in the lab, fitting, minor adjustments, and patient education on donning, doffing, and skin checks. Documentation includes the medical necessity tied to the underlying diagnosis, description of the modification as an addition to a lower extremity above-knee wooden socket, materials used, time in service, and the prosthetist or orthotist taxonomy and licensing.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
11 | Primary procedure | When this socket addition is the primary service provided during the encounter |
22 | Increased procedural services |