Billing and Reimbursement for Ambulance CPT Codes and Modifiers A0425, A0426, A0427, A0428, A0429, A0432, A0433, and A0434


Ambulance and emergency services are billable events, and all insurance companies including Medicare and Medicaid pay for them.  Coding and billing for ambulance services can be complicated because of the unique and detailed modifiers, and the various modes of transport include ground, water, fixed wing, and rotary wing.  RPM Billing LLC has certified ambulance billers and coders on staff, and we are committed to working closely with our clients to provide excellent service and results in ambulance billing and coding.  This blog is intended to provide helpful information for people looking for help with ambulance billing and coding.

Ambulance reimbursement rates can vary widely based on the services provided to each patient.  The coding and billing should accurately represent the services provided.  This starts with the clinical documentation recorded by the healthcare providers during the case.  Coding and billing is strictly based on that documentation, so the documentation must be complete and accurate.  An electronic medical record system can help providers with gathering and organizing the clinical documentation.  Additionally, firms such as PWW ( are experts at staff training and certifications, legal advice and support, and compliance reviews, and RPM Billing LLC has expertise in ambulance billing and a commitment to excellent service and results.  When clinical documentation is done well, then coding and billing can optimize results and reimbursements. 

RPM Billing LLC is a full service billing firm which helps ambulance providers appropriately optimize their reimbursement rates, billing and coding accuracy, and revenue cycle processes.
— Jonathan Marshall, MBA, President of RPM Billing LLC

While the number of CPT codes used in ambulance billing is relatively low, the modifiers are very unique and the complicating factors can have a significant impact on reimbursement.  Required details can include:

-          Pick-up and drop-off location types

-          Clinical severity of the patient

-          If the service qualifies for the rural or even “super-rural” multiplier

-          How many miles were actually traveled compared to how many miles could have been traveled

-          Whether or not the service qualifies as Advanced Life Support or Basic Life Support

-          Whether or not the service requires an ABN

-          If the services are provided in a ground, water, fixed wing, or rotary wing vehicle

-          And more 

Here is a brief example of some potentially counterintuitive differences between coding and billing for Advanced Life Support and Basic Life Support.  Advanced Life Support can be billed even if all patient services provided during the trip do not meet Advanced Life Support criteria, if the crew and ambulance vehicle are certified to provide advanced services, and they provided at least one Advanced Life Support assessment or intervention.  Alternatively, Basic Life Support should be billed if the crew and ambulance vehicle are only certified for Basic Life Support, even if Advanced Life Support services are provided during the trip.

The CPT codes available for ambulance coding and billing include:

A0425 – Ground mileage, quantity is per mile, and the reimbursement for mileage is generally based on the insurance company’s perception of who is closest appropriate provider

A0426 – Advanced Life Support Level 1, Non-Emergency

A0427 – Advanced Life Support Level 1, Emergency

A0428 – Basic Life Support, Non-Emergency

A0429 – Basic Life Support, Emergency

A0432 – Paramedic Intercept

A0433 – Advanced Life Support Level 2, Emergency or Non-Emergency

A0434 – Specialty Care Transport

Modifiers for origin and destination are two characters, and are designed to show first the origin and second the destination.  Some of the available modifiers include, but are not limited to:

D – Diagnostic or therapeutic site

E – Residential, domiciliary, or custodial facility

G – Hospital-based dialysis facility

H – Hospital

I – Site of transfer between modes of transport

J – Non-hospital based dialysis center

N – Skilled nursing facility

P – Physician’s office

R – Residence

S – Scene of accident

X – Intermediate stop at physician’s office en route to hospital

So, for a patient who is being transferred from a physician’s office to a hospital, the origin/destination modifier would be “PH”.  And for a patient who is being transferred via flight ambulance from the airport, where a ground ambulance is dropping off the patient, to the receiving hospital’s helipad, the origin/destination modifier would be “IH”.

Ambulance billing and coding may also include second modifiers to be included after the origin and destination modifier.  These can include but are not limited to:

CR – Related to a catastrophe or declared disaster

GA – ABN was required and obtained

GM – Multiple patient transport

GW – Hospice patient, unrelated to hospice diagnosis

GX – ABN was optional and obtained

GY – Service was non-covered because it is statutorily excluded (examples exist)

GZ – ABN was required but not obtained

QJ – Incarcerated patient

QL – Patient pronounced dead

QM – Under arrangement

QN – Provider of services (when ambulance service is furnished by receiving hospital)

So, for two patients who are being transferred from the scene of an accident to a hospital in the same ambulance, both of their bills should have the modifier “SHGM”.

Medicare, Medicaid, and commercial insurance companies all pay widely different rates for ambulance services.  RPM Billing LLC is a full service billing firm which helps ambulance providers appropriately optimize their reimbursement rates, billing and coding accuracy, and revenue cycle processes.  Our approach is based on our commitment to excellent service and results, which includes specifics such as genuine and constant teamwork with our clients, designing customized processes by working with our clients to understand their business, and collecting 100% of the insurance dollars that are available.

RPM Billing LLC is a medical billing and consulting firm based in Las Vegas and Reno, Nevada, serving doctors, hospitals, surgery centers, rehab centers, ambulance providers, and other healthcare providers nationwide. We have an experienced billing team, and we work closely with our clients to make sure 100% of their bills get paid appropriately and timely. Led by Jonathan Marshall, who holds a Healthcare MBA and two decades of experience as CEO, CFO, and COO of hospitals and physician practices, RPM Billing was created as the answer to all of the overpriced and underperforming billing offices out there. We are 100% committed to excellent service, processes, bottom line results, and ethics. To contact us for a free review of your company’s opportunities to improve revenues, please call us at 775-501-9820, email us at, or visit us at Thank