A4366 — Ostomy vent, any type, each
A4366 is a HCPCS Level II code for ostomy vent, any type, each. It belongs to the Transportation, Medical & Surgical Supplies, Administrative 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.
Physician fee schedule statusX
Statutory exclusion. The item or service is not within the statutory definition of 'physician services', so the fee schedule never pays it.
Global period: XXX
Want the dollar amount for your locality? The fee calculator applies your GPCI and the current conversion factor.
Medically Unlikely Edits — units per day
The most units of A4366 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
- 1 unit MAI 3 — Date of Service Edit: Clinical · Clinical: CMS Workgroup
- outpatient
- 1 unit MAI 3 — Date of Service Edit: Clinical · Clinical: CMS Workgroup
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 A4366
- Long descriptor
- Ostomy vent, any type, each
- Short descriptor
- Ostomy vent
- Added
- January 1, 2004
- BETOS
- D1F
- Pricing indicator
- 37 — 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.
Ostomy, tracheostomy and urological supplies. Price subject to floors and ceilings.
Codes adjacent to A4366
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If A4366 is not quite right, the correct code is very often within a few positions of it.
- A4356External urethral clamp or compression device (not to be used for catheter clamp), each
- A4357Bedside drainage bag, day or night, with or without anti-reflux device, with or without tube, each
- A4358Urinary drainage bag, leg or abdomen, vinyl, with or without tube, with straps, each
- A4360Disposable external urethral clamp or compression device, with pad and/or pouch, each
- A4361Ostomy faceplate, each
- A4362Skin barrier; solid, 4 x 4 or equivalent; each
- A4363Ostomy clamp, any type, replacement only, each
- A4364Adhesive, liquid or equal, any type, per oz
- A4367Ostomy belt, each
- A4368Ostomy filter, any type, each
- A4369Ostomy skin barrier, liquid (spray, brush, etc.), per oz
- A4371Ostomy skin barrier, powder, per oz
- A4372Ostomy skin barrier, solid 4 x 4 or equivalent, standard wear, with built-in convexity, each
- A4373Ostomy skin barrier, with flange (solid, flexible or accordion), with built-in convexity, any size, each
- A4375Ostomy pouch, drainable, with faceplate attached, plastic, each
- A4376Ostomy pouch, drainable, with faceplate attached, rubber, each
Questions about A4366
What is HCPCS code A4366?
A4366 is a HCPCS Level II code for ostomy vent, any type, each. It sits in the Transportation, Medical & Surgical Supplies, Administrative section.
Does Medicare cover A4366?
The CMS HCPCS file marks A4366 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.
How is A4366 paid under the physician fee schedule?
A4366 carries PFS status code X. Statutory exclusion. The item or service is not within the statutory definition of 'physician services', so the fee schedule never pays it.