The need for ambulatory services has seen an increase in recent years, and as a result ambulance transport claims have also risen. Payers generally cover ambulance services for patients whose medical condition is such that air transport is medically necessary. EMS Transport Coding is a unique coding set of non-physician provider services, where medical necessity is always considered. To ensure transport is medically necessary, you must consider both the patient’s condition and the method of transportation.

Steps include:

  1. Identify emergency vs nonemergency response: CMS defines an emergency response as “responding immediately at the BLS or ALS1 level of service to a 911 call or the equivalent”. An immediate response is defined as a response by the ambulance supplier that begins as quickly as possible to the call. All scheduled transports are considered non-emergency, and include routine transports to nursing home, patient homes and ESRD facilities.
  2. Identify the patient’s condition and the method of transport to a health facility.
  3. Identify the type and level of care provided by responders.

10 HCPCS Level II procedure codes for ambulance services:

Ground ambulance services

  • A0425- Ground mileage, per statue mile
  • A0426- Ambulance service, advanced life support, nonemergency transport, level 1(ALS1)
  • A0427- Ambulance service advanced life support, emergency transport, level 1(ALS1 – emergency)
  • A0428- Ambulance service, basic life support, nonemergency transport(BLS)
  • A0429- Ambulance service, basic life support, emergency transport (BLS- emergency)
  • A0433- Advanced life support, level 2(ALS2)
  • A0434- Specialty care transport(SCT)

Air ambulance services

  • A0430 – Ambulance service, conventional air services, transport, one way (fixed wing)
    A0431-Ambulance service, conventional air services, transport, one way (rotary wing)
  • A0888 – Non covered ambulance mileage, per mile

In addition to the HCPCS level II procedure codes a unique set of modifiers are required to identify the origin and destination.

Common modifiers for ambulance services:


Specialty modifiers for ambulance services includes origin and destination codes and their descriptions:

D, E, G, H, I, J, N, P, R, S, X