A0431 HCPCS code: Ambulance service, conventional air services, transport, one way (rotary wing)
A0431 is the HCPCS Level II code for ambulance service, conventional air services, transport, one way (rotary wing). In 2024 Medicare paid an average of $4,467.11 per service for A0431 across 65,581 services. Its Medicare coverage code is C (Carrier judgment): Coverage is decided by the Medicare contractor (MAC) case by case. The NCCI unit limit is 1 per day on outpatient hospital claims. Medicare volume fell 2% from 2022 to 2024 (66,938 to 65,581 services). In 2024, about 356 clinicians billed Medicare for A0431 for 62,458 beneficiaries; Alabama, Texas, Oregon accounted for 32% of services.
Code details
| Field | Value |
|---|---|
| Section | A codes — Transportation, medical/surgical supplies and miscellaneous |
| Coverage code | C — Carrier judgment |
| Pricing indicator | 52 |
| BETOS category | O1A — Ambulance |
| Added | 2001-01-01 |
| Last action effective | 2001-01-01 |
Who bills A0431 (2024)
| Measure | Value |
|---|---|
| Clinicians billing (by place of service) | 356 |
| Medicare beneficiaries | 62,458 |
| States with claims | 42 |
| Share of services in top 3 states (Alabama, Texas, Oregon) | 32% |
Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.
Medicare utilization for A0431, 2022–2024
| Year | Services | Beneficiaries | Avg. allowed | Avg. paid |
|---|---|---|---|---|
| 2022 | 66,938 | 64,085 | $5,060.46 | $4,031.21 |
| 2023 | 66,776 | 63,724 | $5,462.77 | $4,348.03 |
| 2024 | 65,581 | 62,458 | $5,614.02 | $4,467.11 |
States with the most A0431 services (2024)
| State | Services | Avg. paid |
|---|---|---|
| Alabama | 12,993 | $4,322.78 |
| Texas | 4,320 | $4,486.31 |
| Oregon | 3,765 | $4,808.87 |
| Missouri | 3,174 | $4,550.84 |
| Tennessee | 2,690 | $4,527.13 |
NCCI unit limits (MUE)
| Claim type | Max units per day | Rationale |
|---|---|---|
| outpatient hospital claims | 1 | Clinical: Data |
| practitioner claims | 1 | Clinical: Data |
What changed for A0431
- 2001-01-01: A0431 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 A0431?
A0431 is the HCPCS Level II code for ambulance service, conventional air services, transport, one way (rotary wing). Short descriptor: "Rotary wing air transport".
How much does Medicare pay for A0431?
In 2024, the average Medicare payment was $4,467.11 per service (average allowed $5,614.02).
Does Medicare cover A0431?
Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.
How many units of A0431 can be billed per day?
1 on outpatient hospital claims; 1 on practitioner claims (NCCI medically unlikely edits).
Related A04 codes
- A0420 — Ambulance waiting time (als or bls), one half (1/2) hour increments
- 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)
- 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 A0431
- Watch A0431 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A0431
Sources: CMS HCPCS Level II release October 2026; 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.