L5661 — Addition to lower extremity, socket insert, multi-durometer symes
L5661 is a HCPCS Level II code for addition to lower extremity, socket insert, multi-durometer symes. It belongs to the Orthotic and Prosthetic Procedures and Devices section. Whether Medicare pays it depends on the coverage rule below.
Medicare coverage: Carrier judgment
Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q3-Jul. This states Medicare’s position on the code, not on your particular claim.
Medically Unlikely Edits — units per day
The most units of L5661 Medicare will pay on one date of service. Bill more on a single line and it is denied. The limit is not the same in every setting, so the row that matters is the one matching the claim you are building.
- practitioner
- 0 — never payable MAI 3 — Date of Service Edit: Clinical · CMS Policy
- outpatient
- 2 units MAI 2 — Date of Service Edit: Policy · Anatomic Consideration
- DME supplier
- 2 units MAI 3 — Date of Service Edit: Clinical · Anatomic Consideration
The adjudication indicator decides whether exceeding the limit is worth appealing at all: MAI 1 is a line edit you can support with documentation, MAI 3 is a date-of-service edit that is also appealable, and MAI 2 is absolute — no documentation overrides it. CMS MUE 2026Q3.
The CMS record for L5661
- Long descriptor
- Addition to lower extremity, socket insert, multi-durometer symes
- Short descriptor
- Multi-durometer symes
- Added
- January 1, 1988
- BETOS
- D1F
- Pricing indicator
- 38 — DMEPOS
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service — CMS's own analytic grouping.
Orthotics, prosthetics, prosthetic devices and vision services. Price subject to floors and ceilings.
Codes adjacent to L5661
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If L5661 is not quite right, the correct code is very often within a few positions of it.
- L5651Addition to lower extremity, above knee, flexible inner socket, external frame
- L5652Addition to lower extremity, suction suspension, above knee or knee disarticulation socket
- L5653Addition to lower extremity, knee disarticulation, expandable wall socket
- L5654Addition to lower extremity, socket insert, symes, (kemblo, pelite, aliplast, plastazote or equal)
- L5655Addition to lower extremity, socket insert, below knee (kemblo, pelite, aliplast, plastazote or equal)
- L5656Addition to lower extremity, socket insert, knee disarticulation (kemblo, pelite, aliplast, plastazote or equal)
- L5657Addition to lower extremity prosthesis, manual/automated adjustable air, fluid, gel or equal socket insert for limb volume management, any materials
- L5658Addition to lower extremity, socket insert, above knee (kemblo, pelite, aliplast, plastazote or equal)
- L5665Addition to lower extremity, socket insert, multi-durometer, below knee
- L5666Addition to lower extremity, below knee, cuff suspension
- L5668Addition to lower extremity, below knee, molded distal cushion
- L5670Addition to lower extremity, below knee, molded supracondylar suspension ('pts' or similar)
- L5671Addition to lower extremity, below knee / above knee suspension locking mechanism (shuttle, lanyard or equal), excludes socket insert
- L5672Addition to lower extremity, below knee, removable medial brim suspension
- L5673Addition to lower extremity, below knee/above knee, custom fabricated from existing mold or prefabricated, socket insert, silicone gel, elastomeric, or equal, with or without perforations, with or without breathable material, for use with locking mechanism
- L5676Additions to lower extremity, below knee, knee joints, single axis, pair
Questions about L5661
What is HCPCS code L5661?
L5661 is a HCPCS Level II code for addition to lower extremity, socket insert, multi-durometer symes. It sits in the Orthotic and Prosthetic Procedures and Devices section.
Does Medicare cover L5661?
The CMS HCPCS file marks L5661 as "Carrier judgment". Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.