A0420 HCPCS code: Ambulance waiting time (als or bls), one half (1/2) hour increments
A0420 is the HCPCS Level II code for ambulance waiting time (als or bls), one half (1/2) hour increments. Its Medicare coverage code is I (Not payable by Medicare): Medicare does not pay separately under this code; another code applies.
Code details
| Field | Value |
|---|---|
| Section | A codes — Transportation, medical/surgical supplies and miscellaneous |
| Coverage code | I — Not payable by Medicare |
| Pricing indicator | 00 — Not separately priced by Medicare |
| BETOS category | O1A — Ambulance |
| Added | 1995-01-01 |
| Last action effective | 2014-01-01 |
What changed for A0420
- 1995-01-01: A0420 added to HCPCS Level II
- Next scheduled CMS quarterly update (HCPCS and DMEPOS fee schedule): 2027-01-01
Frequently asked questions
What is HCPCS code A0420?
A0420 is the HCPCS Level II code for ambulance waiting time (als or bls), one half (1/2) hour increments. Short descriptor: "Ambulance waiting 1/2 hr".
Does Medicare cover A0420?
Coverage code I — Not payable by Medicare. Medicare does not pay separately under this code; another code applies.
Related A04 codes
- A0422 — Ambulance (als or bls) oxygen and oxygen supplies, life sustaining situation
- A0424 — Extra ambulance attendant, ground (als or bls) or air (fixed or rotary winged); (requires medical review)
- A0425 — Ground mileage, per statute mile
- A0426 — Ambulance service, advanced life support, non-emergency transport, level 1 (als 1)
- A0427 — Ambulance service, advanced life support, emergency transport, level 1 (als 1 - emergency)
- A0428 — Ambulance service, basic life support, non-emergency transport, (bls)
- A0429 — Ambulance service, basic life support, emergency transport (bls-emergency)
- A0430 — Ambulance service, conventional air services, transport, one way (fixed wing)
- A0431 — Ambulance service, conventional air services, transport, one way (rotary wing)
- A0432 — Paramedic intercept (pi), rural area, transport furnished by a volunteer ambulance company which is prohibited by state law from billing third party payers
- A0433 — Advanced life support, level 2 (als 2)
- A0434 — Specialty care transport (sct)
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Next steps
- Run a reimbursement report for a device billed under A0420
- Watch A0420 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A0420
Sources: CMS HCPCS Level II release October 2025; CMS DMEPOS fee schedule; CMS NCCI MUE tables; CMS Medicare utilization (physician and DME supplier files); CMS Medicare Coverage Database articles. Fees are Medicare allowables, not commercial rates. Not billing or legal advice.