Billing codes
A0425 Billing Code: Ground Mileage per Statute Mile on Ambulance and NEMT Claims
Overview
A0425 is the HCPCS Level II code for ground mileage, per statute mile. It is not a CPT code. Medicare pays it only as ambulance mileage: $9.33 a loaded mile for urban pickups and $9.42 for rural ones in 2026. Some Medicaid programs use it for van miles: Indiana pays $1.67 a mile past the first 10, with U3 or U5, and Illinois pays $0.80 to $1.61 by county.
- A0425 is a HCPCS Level II code kept by CMS, one letter and four digits. A form that asks for its CPT code means this code.
- Medicare pays A0425 only on ambulance claims, only for loaded miles, and wants tenths of a mile on trips under 100 miles.
- Indiana bills walk-on and wheelchair van miles on A0425 with U3 or U5: $1.67 a mile from January 1, 2026, and $1.72 from January 1, 2027.
- Illinois pays service car and medicar miles on A0425 by county, from $0.80 to $1.61 a mile as of January 1, 2026.
- Medi-Cal's manual and Ohio keep A0425 for ambulances, with van miles on A0380 and S0209. A health plan such as IEHP may use its own codes.
What A0425 means
CMS lists A0425 in the national HCPCS code set as “Ground mileage, per statute mile.” The October 2026 quarterly file shows it has been in the set since January 1, 2001. It is a per-mile code: one unit for each mile the patient rides.
Billers often call it a CPT code, but it is a HCPCS Level II code, the one-letter, four-digit set CMS keeps for services outside the doctors’ CPT codes. See HCPCS vs CPT for how the two sets differ.
A0425 sits among the ambulance codes in the HCPCS file. Two older codes, A0380 for basic life support mileage and A0390 for advanced life support mileage, are marked not payable by Medicare in the same file and point to A0425 instead. So one ground mileage code now covers every level of ambulance care, and the Medicare manual lists A0425 for both.
A mileage line never stands alone. Medicare’s ambulance manual says each trip generally takes two lines of coding, one for the service and one for the mileage. The first line is the base rate, and A0425 carries the loaded miles.
How Medicare pays A0425
Medicare pays A0425 only on ambulance claims, under the ambulance fee schedule. Three rules decide the units:
- Loaded miles only. Under 42 CFR 414.610(c)(3), payment is based on loaded miles. Section 20.2 of the claims manual counts them from the pickup of the patient to arrival at the destination and says separate charges for unloaded miles are denied.
- Tenths of a mile. Section 30.1.2 says that on trips up to 100 covered miles, you round the total up to the next tenth and report it with the decimal, such as 99.9. At 100 miles or more, you round up to the next whole mile. A trip under 1 mile is written with a zero first, such as 0.9.
- The closest appropriate facility. Miles past the closest available facility cannot be billed to Medicare on A0425. Section 30.2.4 puts them on A0888, noncovered ambulance mileage.
CMS’s 2026 fee schedule file, dated December 8, 2025, lists A0425 at a $9.15 base rate, $9.33 a mile for urban pickups, and $9.42 for rural pickups, with $14.13 for each of the first 17 rural miles. The urban and rural rates include the 2 percent and 3 percent add-ons that section 6203 of the Consolidated Appropriations Act, 2026 extended through December 31, 2027, so they are what Medicare pays on 2026 trips. The $14.13 figure comes from 42 CFR 414.610(c)(5), which raises the mileage rate by 50 percent for the first 17 miles when the pickup is in a rural area.
None of this pays for a van. Medicare does not cover wheelchair van or sedan trips, so a van company never bills Medicare on A0425. See does Medicare cover NEMT and NEMT vs ambulance.
Medicaid programs that pay van miles on A0425
Because Medicaid programs choose their own codes, some put non-ambulance miles on A0425. Indiana and Illinois publish their rules and rates, and each pays far less for a van mile than for an ambulance mile on the same code. Illinois pays private ambulances $7.84 a mile on A0425 in every county (January 1, 2026).
| Program and service | What goes in box 24D | Rate per mile |
|---|---|---|
| Indiana, walk-on rides (commercial ambulatory service) | A0425 U3 | $1.67 (January 1, 2026) |
| Indiana, wheelchair van rides (nonambulatory service) | A0425 U5 | $1.67 (January 1, 2026) |
| Indiana, ambulance (advanced or basic life support) | A0425 | $9.15 (January 1, 2026) |
| Illinois, service car or medicar, Cook, DuPage, Kane, Lake, McHenry, and Will counties | A0425 | $1.03 (January 1, 2026) |
| Illinois, service car or medicar, Madison and St. Clair counties | A0425 | $1.61 (January 1, 2026) |
| Illinois, service car or medicar, other counties | A0425 | $0.80 (January 1, 2026) |
| Illinois, taxi | A0425 | $0.91, or $1.61 in Madison and St. Clair (January 1, 2026) |
Indiana’s rules for A0425
Indiana’s Transportation Services module (version 6.1, published August 19, 2025) adds these rules:
- Only trips over 10 miles pay mileage. Indiana deducts the first 10 miles of each one-way walk-on or wheelchair trip itself, so bill every mile, including the first 10. On a trip under 10 miles, mileage is optional, and a mileage line you bill anyway is denied.
- Whole miles. Round to the nearest mile: 15.0 to 15.4 miles bills as 15, and 15.5 to 16.0 bills as 16.
- One line per round trip. Put a round trip’s miles on one detail line. Do not split them.
- Origin and destination on both lines. The base code and the mileage code each carry the origin and destination modifier.
- No S0215. Indiana calls S0215 nonreimbursable, so walk-on miles go on A0425 U3.
- No U modifier means ambulance. Plain A0425 is for advanced or basic life support transports only.
Indiana’s fee schedule page says these rates apply to fee-for-service claims and are also the minimum rates for every Indiana Medicaid managed care plan. Its preview of 2027 rates lists A0425 U3 and U5 at $1.72 a mile, and plain A0425 at $9.33, from January 1, 2027. See the Indiana state guide.
Illinois’s rules for A0425
Illinois’s transportation handbook (March 11, 2024) pays medicar and service car trips a base rate plus a loaded mileage rate, and lists charges for mileage other than loaded miles as non-covered. When two Medicaid riders share the vehicle, each gets a separate claim, but only the first rider picked up gets mileage, limited to the shortest route between that rider’s pickup and destination. The fee schedule notes that all non-emergency transportation needs prior approval. See the Illinois state guide.
Programs that keep A0425 for ambulances
Other programs keep A0425 for ambulances and bill van miles on a van code. Two examples:
- Medi-Cal. The ground transportation manual (page updated August 2020) bills wheelchair van and litter van miles on A0380 and ambulance miles on A0425. Total miles from pickup to destination, plus return miles on a round trip, go in box 24G, and the full pickup and destination addresses go in box 19. A Medi-Cal plan can use its own codes: Inland Empire Health Plan’s billing guidelines (posted May 1, 2024) put door-to-door trip miles on A0425 and wheelchair and gurney miles on A0380. See IEHP.
- Ohio Medicaid. For fee-for-service trips, the appendix to rule 5160-15-28, in effect since August 1, 2026, pays A0425 at $5.05 a mile as ground ambulance mileage and wheelchair van miles on S0209 at $1.30. Even when an ambulance vehicle runs a wheelchair van trip, Ohio bills it with the U3 modifier on A0130, S0209, and T2001, not on A0425.
If your fee schedule has no A0425 line for your provider type, bill the mileage code it does list. The full list is in NEMT billing codes.
A0425 on a claim: worked examples
The procedure code and up to four modifiers go in box 24D of the CMS-1500, and the miles go in box 24G as units, under the NUCC instructions (version 13.0, July 2025). These examples use each state’s published rates. The trips are example numbers.
| Program and trip | Base line | A0425 line | Total |
|---|---|---|---|
| Indiana, wheelchair van, 18.4 loaded miles from home to a freestanding dialysis center | A0130 RJ: $31.79 | A0425 U5 RJ, 18 units: 8 paid miles x $1.67 = $13.36 | $45.15 |
| Illinois, service car, 18 loaded miles in Cook County | A0120: $20.00 | 18 x $1.03 = $18.54 | $38.54 |
| Illinois, service car, 18 loaded miles in Adams County | A0120: $20.00 | 18 x $0.80 = $14.40 | $34.40 |
In Indiana, 18.4 miles rounds to 18 units, and the state pays the 8 miles left after its 10-mile deduction. On a Medicare ambulance claim, the same distance would bill as 18.4. Check each state’s code pairs and modifiers in its own manual before you copy a line. See NEMT mileage billing for how to measure and document the miles.
Mistakes that get A0425 lines denied
- Plain A0425 on an Indiana van trip. Without U3 or U5, the line reads as ambulance mileage.
- A0425 where your state uses another code. Medi-Cal wants A0380 for van miles, and Ohio wants S0209.
- Unloaded miles. Medicare denies them, and Illinois does not cover them.
- Split mileage. Indiana wants a round trip’s miles on one line.
- The wrong rounding. Medicare wants tenths, and Indiana wants whole miles.
- Miles for every rider on a shared ride. Illinois and Indiana pay mileage for the first rider only.
For fixes, see NEMT claim denials.
Frequently asked questions
Is A0425 a CPT code?
No. A0425 is a HCPCS Level II code, from the national set CMS keeps: one letter followed by four digits. CPT codes are HCPCS Level I, the five-character codes the American Medical Association keeps for services by doctors and other clinicians. Box 24D of the CMS-1500 takes either kind, so when a payer or a form asks for the CPT code of a mileage line, give A0425 with its modifiers.
Does Medicare pay A0425 for a wheelchair van trip?
No. Medicare pays A0425 as the mileage on a covered ambulance transport. In the October 2026 HCPCS file, A0425 carries coverage code C, carrier judgment, while the wheelchair van code A0130 and the van mileage codes S0209 and S0215 carry coverage code I, not payable by Medicare. Van trips are paid by Medicaid, a health plan, or a broker, under their own codes.
What is the difference between A0425 and A0380?
A0380 is "BLS mileage (per mile)," an older ambulance mileage code. The October 2026 HCPCS file marks it not payable by Medicare and points billers to A0425, which covers ground mileage at every ambulance level. Medi-Cal still uses A0380, for wheelchair van and litter van miles only, and keeps A0425 for ambulances.
How do I round miles on an A0425 line?
Follow the payer. Medicare wants miles rounded up to the next tenth on trips up to 100 covered miles, such as 18.4, and rounded up to the next whole mile at 100 miles or more. Indiana Medicaid wants whole miles rounded to the nearest mile: 15.0 to 15.4 miles bills as 15, and 15.5 to 16.0 bills as 16 (module version 6.1, August 19, 2025).
Will Indiana's A0425 rate change in 2027?
Yes. Indiana Medicaid's preview of 2027 rates lists A0425 with U3 or U5 at $1.72 a mile and ambulance mileage on plain A0425 at $9.33 a mile, both for dates of service on and after January 1, 2027. The 2026 rates are $1.67 and $9.15.