L4020 — Replace quadrilateral socket brim, molded to patient model
L4020 is a HCPCS Level II code for replace quadrilateral socket brim, molded to patient model. 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 L4020 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 L4020
- Long descriptor
- Replace quadrilateral socket brim, molded to patient model
- Short descriptor
- Replace quadlat socket brim
- Added
- January 1, 1985
- 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 L4020
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If L4020 is not quite right, the correct code is very often within a few positions of it.
- L3981Upper extremity fracture orthosis, humeral, prefabricated, includes shoulder cap design, with or without joints, forearm section, may include soft interface, straps, includes fitting and adjustments
- L3982Upper extremity fracture orthosis, radius/ulnar, prefabricated, includes fitting and adjustment
- L3984Upper extremity fracture orthosis, wrist, prefabricated, includes fitting and adjustment
- L3995Addition to upper extremity orthosis, sock, fracture or equal, each
- L3999Upper limb orthosis, not otherwise specified
- L4000Replace girdle for spinal orthosis (ctlso or so)
- L4002Replacement strap, any orthosis, includes all components, any length, any type
- L4010Replace trilateral socket brim
- L4030Replace quadrilateral socket brim, custom fitted
- L4040Replace molded thigh lacer, for custom fabricated orthosis only
- L4045Replace non-molded thigh lacer, for custom fabricated orthosis only
- L4050Replace molded calf lacer, for custom fabricated orthosis only
- L4055Replace non-molded calf lacer, for custom fabricated orthosis only
- L4060Replace high roll cuff
- L4070Replace proximal and distal upright for kafo
- L4080Replace metal bands kafo, proximal thigh
Questions about L4020
What is HCPCS code L4020?
L4020 is a HCPCS Level II code for replace quadrilateral socket brim, molded to patient model. It sits in the Orthotic and Prosthetic Procedures and Devices section.
Does Medicare cover L4020?
The CMS HCPCS file marks L4020 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.