A0425: Ground ambulance mileage code
A0425 is the HCPCS code for ground mileage, per statute mile. It is billed on its own line next to an ambulance base code such as A0428, counting every loaded mile as a unit. Medicare pays it only for ambulance trips. A few Medicaid programs also use it for van and taxi miles, including Indiana and Illinois, while Colorado now limits it to ambulances.
On this page
What A0425 pays for
A0425 is the mileage line of a ground ambulance trip. Its official HCPCS descriptor, unchanged in the October 2026 file, is “Ground mileage, per statute mile.” It entered the code set on January 1, 2001, and unlike the non-emergency mileage codes, Medicare prices it under the ambulance fee schedule.
Medicare uses one ground mileage rate for every level of ambulance service, so a basic life support run and an advanced life support run bill the same code for miles. The base code, such as A0428 for a non-emergency BLS transport, goes on one line and A0425 on the next. Only loaded miles count, from pickup to arrival with the patient on board. Medicare denies separate charges for unloaded miles, on the view that their cost is already built into the base charge and the loaded-mile rate. HCPCS keeps a separate code, A0888, for noncovered ambulance mileage such as miles beyond the closest appropriate facility.
How Medicare wants the miles reported
Medicare’s ambulance billing chapter sets precise rounding rules for the unit count:
- Under 100 covered miles: raise the total to the next tenth and keep the decimal, as in 99.9.
- 100 covered miles or more: round up to a whole number and leave out the decimal.
- Under one mile: put a zero before the decimal, as in 0.9.
Two payment rules also reach the mileage line. Since October 1, 2018, Medicare cuts both the base rate and the mileage by 23 percent for non-emergency BLS dialysis trips for beneficiaries with end-stage renal disease. And under the prior authorization model for repetitive, scheduled trips, A0425 rides along with the approved transport code instead of needing its own approval.
How Medicaid programs use A0425
Medicaid programs choose their own codes, and A0425 shows how far they drift apart. The same code can mean ambulance miles in one state and taxi miles in the next.
| Program | How A0425 is used | 2026 rate |
|---|---|---|
| Indiana | Ambulance miles with no modifier. U3 marks ambulatory van miles and U5 wheelchair van miles. | $9.15 a mile for ambulance; $1.67 with U3 or U5 (January 1, 2026) |
| Illinois | Miles on taxi, service car, and medicar trips (medicar is the Illinois term for a wheelchair van) | Taxi $0.91, or $1.61 in Madison and St. Clair. Service car and medicar: $1.03 for Cook, DuPage, Kane, Lake, McHenry, and Will; $1.61 for Madison and St. Clair; $0.80 across the remaining counties (January 1, 2026) |
| Colorado | Ambulance miles only since July 1, 2025. Mobility van and taxi miles moved to S0215, and wheelchair van miles use S0209. | $6.28 a mile (July 1, 2026) |
| South Dakota | Loaded ambulance miles in whole numbers, and only one mileage allowance for a trip no matter how many people ride | $9.00 a mile (July 1, 2026) |
| Ohio | Ground ambulance miles | $5.05 a mile (rate last changed January 1, 2024) |
Two programs split ambulance miles further. Medi-Cal keeps A0425 for ambulances and puts wheelchair and litter van mileage on A0380. Oregon’s provider guide lists A0425 for emergency ambulance miles but S0215 for non-emergency ambulance miles.
The mileage conditions travel with the code. On Indiana ambulatory and wheelchair trips, the state takes 10 miles off every one-way leg before paying, but it still wants the full round-trip distance reported on a single line. When several Illinois riders share a vehicle, only the rider collected first gets mileage. Indiana also does not apply the 250-unit medically unlikely edit to A0425, so a long trip can bill more than 250 miles on one date.
A0425 compared with S0209, S0215, and T2049
| Code | HCPCS descriptor | Usual vehicle | Medicare |
|---|---|---|---|
| A0425 | Ground mileage, per statute mile | Ground ambulance, plus vans and taxis in a few states | Priced for covered ambulance trips |
| S0209 | Wheelchair van, mileage, per mile | Wheelchair van | Not payable |
| S0215 | Non-emergency transportation; mileage, per mile | Ambulatory vehicles and taxis in several states | Not payable |
| T2049 | Non-emergency transportation; stretcher van, mileage; per mile | Stretcher van | Not payable |
Most A0425 errors come from applying one program’s rules in another. A van company in Colorado that still bills A0425 is using a code retired for its trips. An Indiana biller who drops the U3 or U5 modifier sends a line that Indiana reserves for ALS and BLS ambulance transports. And the decimals Medicare requires break South Dakota’s rule of whole miles with no decimals. Our guide to NEMT mileage billing covers which miles count, and NEMT billing codes lists the base codes each mileage code pairs with.
Keeping the miles defensible
A mileage line needs a trip record that backs it up. HealthRide keeps GPS-recorded miles for each trip, and its trip log report downloads as a CSV or PDF, which lets you compare billed miles with what the vehicle actually drove.
Frequently asked questions
- Is A0425 ever used for wheelchair van miles?
- In a handful of programs. Indiana pairs A0425 with modifier U5 for wheelchair van miles and U3 for ambulatory van miles, both paying $1.67 a mile in 2026. Illinois uses it for medicar and service car miles. Colorado dropped it for every non-ambulance trip from July 1, 2025, and Medi-Cal sends wheelchair and litter van mileage to A0380. Colorado bills wheelchair van miles as S0209, and South Dakota uses S0209 for secure van miles.
- How does Medicare want A0425 miles rounded?
- For a trip under 100 covered miles, raise the total to the next tenth of a mile and keep the decimal, such as 12.4. At 100 miles or more, drop the decimal and round up to a whole number. A trip under one mile is written with a leading zero, such as 0.6. Medicaid programs often differ: South Dakota and Indiana want whole miles only.
- Does A0425 need its own prior authorization?
- Not under Medicare's prior authorization model for repetitive, scheduled non-emergency ambulance trips. That model reviews the transport codes A0426 and A0428 and treats A0425 as an associated service. Put the mileage line on the claim that carries the transport. If the transport line is denied, the mileage payment can be recouped.
