Ambulance Mileage

Per the CMS Internet Only Manual (IOM), Publication 100-02, Chapter 10, Section 10.3 it states, "As a general rule, only local transportation by ambulance is covered, and therefore, only mileage to the nearest appropriate facility equipped to treat the patient is covered."

Medicare only pays for miles traveled while the patient was on board or "loaded" miles. Medicare does not pay for miles traveled to the point of pick-up.

Air Ambulance

HCPCS Mileage Determination
A0435 (Fixed Wing), A0436 (Rotary Wing)
  • Suppliers must report mileage rounded up to nearest whole number mile
  • If mileage not indicated, defaults "0.1"

Ground/Water Ambulance

HCPCS Mileage Determination
A0425
  • Mileage totaling less than 1 mile, providers/suppliers must include a "0" prior to decimal point. For ambulance mileage HCPCS only, Medicare contractors automatically default "0.1" unit when total mileage units are missing in Item 24G of CMS-1500 claim form
  • Trips totaling 100 miles and less, suppliers must report mileage rounded up to nearest tenth of a mile - Fractional mileage
  • Trips totaling 100 miles and greater, suppliers must report mileage rounded up to nearest whole number mile Medicare contractors will truncate mileage units totaling 100 and greater that are reported with fractional mileage

Reimbursable Situations Which May Cause Additional Mileage

There are occasions when a beneficiary may be transported beyond what is to be considered "the closest facility." If/when this occurs, the ambulance supplier must document the exceptions on the claim. Note in the patient's documentation the circumstances of this transport and include such comments in Item 19 of the CMS-1500 claim form or its equivalent.

  • Blizzard conditions or heavy fog
  • Extensive road construction
  • Specialist/equipment not available at closest hospital (orthopedic surgeon; neurologist)
  • Hospital on diversion (no beds, weather, not taking new patients, etc.)
  • No Fly/Restricted Zone/Medivac - This must be supported by official federal aviation administration (FAA) message of Notice to Airmen (NOTAM) or documented refusal by Air Traffic Controller (ATC)

Non-Reimbursable Situations Which May Cause Additional Mileage

There are also transports that go beyond the closest facility but its reasoning does not fall within the above medically necessary or justified reasons.

  • Beneficiary's family would like him/her to be closer to them, causing additional mileage to incur
  • Beneficiary and/or family does not like the closest facility available

Submit Claim Containing the Below:

  • Bill HCPCS A0425 for covered miles
    • Append Origin/Destination modifier
  • Bill HCPCS code A0888 for non-covered ambulance mileage (per mile), such as miles traveled beyond the closest appropriate facility.
    • Append Origin/Destination modifier
    • Append GY modifier, if beneficiary is liable
    • Do not append GY modifier, if ambulance supplier is liable

Remote Rescues

What if a beneficiary is injured in rock climbing, snowmobiling, on an all-terrain vehicle (ATV), toboggans, hiking, etc. and the EMT/Paramedic provides a rescue in the back country or other remote areas?

Although such a rescue is necessary, the cost of the rescue is bundled into the ambulance base rate, in the same way that oxygen and IV supplies are bundled. Medicare covers mileage from the "time the patient is loaded in the Ambulance" for transport only. No additional mileage is allowed from the site to the ambulance. Distance traveled by toboggan or snowmobile is not counted as loaded mileage because it is considered equivalent to transport by stretcher. Medicare does not provide a separate benefit for these modes of transport until the patient reaches the ambulance.

Resources

Last Updated Sep 28 , 2026