A0422: Ambulance (als or bls) oxygen and oxygen supplies, life sustaining situation
A0422 is a HCPCS Level II code for ambulance (als or bls) oxygen and oxygen supplies, life sustaining situation. It belongs to the Transportation, Medical & Surgical Supplies, Administrative section. Medicare does not pay it: see the coverage note below before you bill it.
Medicare coverage: Not payable by Medicare
Medicare does not pay this code. It may still be valid for another payer, but a Medicare claim carrying it will not be reimbursed.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q4-Oct. This states Medicare’s position on the code, not on your particular claim.
Physician fee schedule statusI
Not valid for Medicare purposes. Medicare uses another code.
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 A0422 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
- 0, never payable MAI 3: Date of Service Edit: Clinical · CMS Policy
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 2026Q4.
The CMS record for A0422
- Long descriptor
- Ambulance (als or bls) oxygen and oxygen supplies, life sustaining situation
- Short descriptor
- Ambulance 02 life sustaining
- Added
- January 1, 1995
- BETOS
- O1A
- Pricing indicator
- 00: Not priced by Part B
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.
Service not separately priced by Part B, not covered, bundled into another service, or used by Part A only.
Codes adjacent to A0422
HCPCS has no hierarchy: related items simply sit next to each other in the numbering. If A0422 is not quite right, the correct code is very often within a few positions of it.
- A0382Bls routine disposable supplies
- A0384Bls specialized service disposable supplies; defibrillation (used by als ambulances and bls ambulances in jurisdictions where defibrillation is permitted in bls ambulances)
- A0390Als mileage (per mile)
- A0392Als specialized service disposable supplies; defibrillation (to be used only in jurisdictions where defibrillation cannot be performed in bls ambulances)
- A0394Als specialized service disposable supplies; iv drug therapy
- A0396Als specialized service disposable supplies; esophageal intubation
- A0398Als routine disposable supplies
- A0420Ambulance waiting time (als or bls), one half (1/2) hour increments
- A0424Extra ambulance attendant, ground (als or bls) or air (fixed or rotary winged); (requires medical review)
- A0425Ground mileage, per statute mile
- A0426Ambulance service, advanced life support, non-emergency transport, level 1 (als 1)
- A0427Ambulance service, advanced life support, emergency transport, level 1 (als 1 - emergency)
- A0428Ambulance service, basic life support, non-emergency transport, (bls)
- A0429Ambulance service, basic life support, emergency transport (bls-emergency)
- A0430Ambulance service, conventional air services, transport, one way (fixed wing)
- A0431Ambulance service, conventional air services, transport, one way (rotary wing)