L5645 — Addition to lower extremity, below knee, flexible inner socket, external frame
L5645 is a HCPCS Level II code for addition to lower extremity, below knee, flexible inner socket, external frame. 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 L5645 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 2 — Date of Service Edit: Policy · 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 L5645
- Long descriptor
- Addition to lower extremity, below knee, flexible inner socket, external frame
- Short descriptor
- Bk flex inner socket ext fra
- 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 L5645
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If L5645 is not quite right, the correct code is very often within a few positions of it.
- L5636Addition to lower extremity, symes type, medial opening socket
- L5637Addition to lower extremity, below knee, total contact
- L5638Addition to lower extremity, below knee, leather socket
- L5639Addition to lower extremity, below knee, wood socket
- L5640Addition to lower extremity, knee disarticulation, leather socket
- L5642Addition to lower extremity, above knee, leather socket
- L5643Addition to lower extremity, hip disarticulation, flexible inner socket, external frame
- L5644Addition to lower extremity, above knee, wood socket
- L5646Addition to lower extremity, below knee, air, fluid, gel or equal, cushion socket
- L5647Addition to lower extremity, below knee suction socket
- L5648Addition to lower extremity, above knee, air, fluid, gel or equal, cushion socket
- L5649Addition to lower extremity, ischial containment/narrow m-l socket
- L5650Additions to lower extremity, total contact, above knee or knee disarticulation socket
- 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
Questions about L5645
What is HCPCS code L5645?
L5645 is a HCPCS Level II code for addition to lower extremity, below knee, flexible inner socket, external frame. It sits in the Orthotic and Prosthetic Procedures and Devices section.
Does Medicare cover L5645?
The CMS HCPCS file marks L5645 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.