HCPCS Code A0425: Ground Mileage, Per Statute Mile

Learn about HCPCS Code A0425 for ground mileage per statute mile in ambulance services, including billing, documentation, emergency and non-emergency use.

Use Code

## **What is ground mileage, per statute mile?** HCPCS Code A0425 is used to bill ground ambulance mileage, calculated per statute mile, for a covered and medically necessary ambulance transport. This code applies to both emergency and non-emergency transports, including interfacility transfers, but only for the portion of the trip when the patient is on board the ambulance (“loaded mileage”). Mileage is measured from the patient’s pickup location to the destination, such as a hospital, skilled nursing facility, or other authorized point of care. It does not include travel to the pickup site or return mileage after the patient has been dropped off. A0425 is almost always reported together with the appropriate base ambulance service code that reflects the level of care provided—such as basic life support (BLS), advanced life support (ALS), or specialty care transport. ## **When to use A0425** - Applied when billing for each statute mile of loaded ground ambulance transport (patient is on board). - Always billed on the same date of service as the corresponding base ambulance code (e.g., A0428 for BLS, A0427 for ALS1 emergency). - Used for both emergency and medically necessary non-emergency transports, as long as the underlying transport itself qualifies for coverage. - Not used for air ambulance services, which have separate mileage codes (A0435 for fixed-wing, A0436 for rotary-wing).

## **HCPCS code A0425 documentation requirements** When submitting A0425, providers should include: - The date of service and the total number of statute miles traveled. - Clear indication of whether transport was emergency transport or non emergency transport. - Supporting documentation showing medical necessity for the ambulance services, including the patient’s condition and reason transport by other means was unsafe. - Pickup and destination details, with full addresses (street, city, ZIP code), such as a hospital, skilled nursing facility, or other authorized point of care, to validate billed mileage.

## **A0425 Billing requirements** A0425 claims must be supported with: - A0425 is always billed per statute mile, and only for covered, medically necessary transports. - It must be linked with the corresponding level of ambulance services rendered (e.g., basic life support, advanced life support, or specialty care transport). - Claims should reflect accurate mileage, verified through mapping or odometer readings. - For Medicare beneficiaries, ensure compliance with medical necessity requirements and apply the correct rural or urban mileage rates as determined by the pickup ZIP code; Medicare does not impose fixed mileage limits but may apply payment adjustments or reductions in certain situations (e.g., repetitive ESRD transports). - Always use the most appropriate HCPCS code for the service provided to avoid denials. - If the patient dies after dispatch but before pickup, providers must still submit two lines (service and mileage), enter the mileage with the appropriate HCPCS code and modifiers, and report a non-covered $1.00 mileage charge flagged as “A0” to prevent patient liability.

## **Other relevant codes** - A0426 – Ambulance service, advanced life support, non-emergency transport, level 1 - A0427 – Ambulance service, advanced life support, emergency transport, Level 1 (ALS1) - A0428 – Ambulance service, basic life support, non-emergency transport, (BLS) - A0429 – Code for Ambulance service, basic life support, emergency transport (BLS-emergency)

Frequently asked questions

No. Mileage (A0425) can only be billed for loaded miles—from pickup to destination. If the patient is pronounced dead before being transported, mileage is not billable.

Providers must document and bill the exact number of loaded statute miles, following Medicare rounding rules (to the nearest 1/10th mile under 100 miles, to the nearest whole mile for 100+ miles).

Yes. Ground mileage (A0425) is billed in addition to the base BLS code (e.g., A0428 for non-emergency or A0429 for emergency) and must be entered as a separate line item.