Clinical UM Guideline
Subject: Ambulance Services: Air and Water
Guideline #: CG-ANC-04 Publish Date: 12/29/2021
Status: Reviewed Last Review Date: 11/11/2021

This document addresses the use of air or water ambulance services. An ambulance is a specially equipped vehicle designed and supplied with materials and devices to provide life-saving and supportive treatments or interventions. Wheel-chair vans or other such vehicles are not so equipped and are not addressed in this document.

Note: Please see the following related documents for additional information:

Clinical Indications

Medically Necessary:

The use of air and water ambulance services is considered medically necessary when all the following criteria are met:

  1. The ambulance must have the necessary equipment and supplies to address the needs of the individual; and
  2. The individual’s condition must be such that any form of transportation other than by ambulance would be medically contraindicated; and
  3. The individual’s condition is such that the time needed to transport by land poses a threat to the individual’s survival or seriously endangers the individual’s health*; or the individual’s location is such that accessibility is only feasible by air or water transportation; and
  4. There is a medical condition that is life threatening or first responders deem to be life threatening, including, but not limited to, the following:
    1. Intracranial bleeding; or
    2. Cardiogenic shock; or
    3. Major burns requiring immediate treatment in a Burn Center; or
    4. Conditions requiring immediate treatment in a Hyperbaric Oxygen Unit; or
    5. Multiple severe injuries; or
    6. Transplants; or
    7. Limb-threatening trauma; or
    8. High risk pregnancy; or
    9. Acute myocardial infarction; if this would enable the individual to receive a more timely medically necessary intervention (such as percutaneous transluminal coronary angioplasty [PTCA] or fibrinolytic therapy).

*Air transportation may be appropriate if the time between identification of the need for transportation until arrival at the intended destination for ground ambulance would be 30 minutes or longer than air transport.

Mileage associated with an air or water ambulance service is considered medically necessary up to the distance required for transport to the nearest appropriate facility.

The use of air and water ambulance services to transport an individual from one hospital to another requires that:

  1. The above criteria must be met, and
  2. The first hospital does not have the required services and facilities to treat the individual.

The use of air and water ambulance services for deceased individuals is considered medically necessary when the above criteria are met and when either of the following is present:

  1. The individual was pronounced dead while in route or upon arrival at the hospital or final destination; or
  2. The individual was pronounced dead by a legally authorized individual (physician or medical examiner) after the ambulance call was made, but prior to pick-up. In these circumstances the response to call is considered medically necessary.

Not Medically Necessary:

All other uses of air and water ambulance services are considered not medically necessary, including, but not limited to, the following:

  1. Transfers from one hospital to another if above criteria not met; or
  2. Transfers from a hospital capable of treating an individual to another hospital primarily for the convenience of the individual or the individual’s family or physician; or
  3. When land transportation is available and the time required to transport the individual by land does not endanger the individual’s life or health; or
  4. Transportation to a facility that is not an acute care hospital, such as a nursing facility, physician’s office or the individual’s home; or
  5. The services are for a transfer of a deceased individual to a funeral home, morgue, or hospital, when the individual was pronounced dead at the scene.

Mileage in excess of the distance from the trip origin to the nearest appropriate facility is considered not medically necessary.


The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services may be Medically Necessary when criteria are met:




Ambulance service, conventional air services, transport, one way (fixed wing)


Ambulance service, conventional air services, transport, one way (rotary wing)


Fixed wing air mileage, per statute mile


Rotary wing air mileage, per statute mile


Unlisted ambulance service [when specified as ambulance service, water transport]


Ambulance service, conventional air services, nonemergency transport, one way (fixed wing)


Ambulance service, conventional air service, nonemergency transport, one way (rotary wing)



ICD-10 Diagnosis



All diagnoses

When services are Not Medically Necessary:
For the procedure codes listed above when criteria are not met or for situations designated in the Clinical Indications section as not medically necessary.

When services are also Not Medically Necessary:
For the following procedure code; or when the code describes a procedure designated in the Clinical Indications section as not medically necessary.




Noncovered ambulance mileage, per mile (e.g., for miles traveled beyond closest appropriate facility)



ICD-10 Diagnosis



All diagnoses

Discussion/General Information

Ambulance transport services involve the use of specially designed and equipped vehicles to transport ill or injured individuals. Ambulance transport may involve the movement of an individual to the nearest hospital for treatment of the individual’s illness or injury, non-emergency medical transport of an individual to another location to obtain medically necessary specialized diagnostic or treatment services, or non-emergency medical transport to a hospital or to an individual’s home. An air ambulance may be a specially equipped aircraft such as a helicopter of airplane or boats. Water ambulances are specially equipped boats. Proper equipment may include ventilation and airway equipment, cardiac equipment (monitoring and defibrillation), immobilization devices, bandages, communication equipment, obstetrical kits, infection control, injury prevention equipment, vascular access equipment, and medications.

In general, an emergency medical condition is defined as a medical condition manifesting itself by acute symptoms of sufficient severity (including severe pain) so that a prudent layperson who possesses an average knowledge of health and medicine, could reasonably expect the absence of immediate medical attention to result in:

Examples of medical emergencies may include illness or injury such as severe chest pains that might indicate a heart attack, slurred speech or weakness that might indicate a stroke, fracture, hemorrhaging, poisoning, major burns, loss of consciousness or respiratory accidents, convulsions, shock and other acute conditions.

The Medicare Benefit Policy Manual (2018) section addressing time needed for ground transportation (10.4.3) states the following:

Differing Statewide Emergency Medical Services (EMS) systems determine the amount and level of basic and advanced life support ground transportation available. However, there are very limited emergency cases where ground transportation is available but the time required to transport the patient by ground as opposed to air endangers the beneficiary’s life or health. As a general guideline, when it would take a ground ambulance 30-60 minutes or more to transport a beneficiary whose medical condition at the time of pick-up required immediate and rapid transport due to the nature and/or severity of the beneficiary’s illness/injury, A/B MACs (A) and (B) should consider air transportation to be appropriate.

A 2020 retrospective study by Stewart and colleagues compared the outcomes of transport between helicopter transport and ground transport for inter-facility transfer of persons with trauma to tertiary trauma centers. Looking at the records of 9880 people who had been initially seen at a non-tertiary trauma center, but were then transferred to a tertiary trauma center, the authors reported on mortality at 72 hours and within the first 2 weeks after arriving at the tertiary trauma center. For those transferred by helicopter, the mean distance between the facilities was 96.7 miles with a mean distance of 69.9 miles for those transferred by ground ambulance. The helicopter transport group showed a decreased 72 hour mortality only for the individuals transferred less than 90 miles. There were no significant differences in mortality for helicopter transport greater than 90 miles, and no significant differences in mortality at 2 weeks for either transport modality.

In 2021, Kunte and colleagues reported on whether air or ground transport led to faster delivery times in interhospital transfer and direct-from-scene transfer of individuals with ischemic stroke to a comprehensive stroke center. In this retrospective review, there were four cohorts: transfer air (n=47), transfer ground (n=68), scene air (n=40) and scene ground (n=50). Three time periods were looked at within the transport process: alarm to emergency medical services (EMS) arrival, EMS arrival to EMS departure, and EMS departure to comprehensive stroke center arrival. Median alarm to EMS arrival time was 27.5 minutes for transfer air, 15.5 minutes for transfer ground, 22 minutes for scene air, and 10 minutes for scene ground. Total on scene time was represented by EMS arrival to EMS departure. Median EMS arrival to EMS departure time was 13 minutes for transfer air, 14 minutes for transfer ground, 7.5 minutes for scene air, and 12 minutes for scene ground. In order to evaluate EMS transfer time not associated with actual travel time, the authors measured the amount of time it took EMS to respond to alarms and prepare the individual for transfer. Those in the transfer cohort had a median alarm to EMS departure of 39 minutes versus 31 minutes for those in the scene cohort. Also in the transfer cohort, transfer air had a median alarm to EMS departure of 44 minutes versus 36 minutes for transfer ground. For those being transported from the scene, scene air median alarm to EMS departure time was 37.5 minutes compared to 25 minutes for scene ground noting air transport had longer EMS time before departure compared to ground transport. Modified Rankin score was used at 90 days after treatment to quantify functional outcomes. There were no significant differences in scores between the groups. The authors did not report whether outcomes were improved. In transporting individuals either between facilities or from scenes, some variables cannot be accounted for such as weather and traffic at the time of transfer.


Peer Reviewed Publications:

  1. Funder KS, Rasmussen LS, Lohse N, et al. The impact of a physician-staffed helicopter on outcome in patients admitted to a stroke unit: a prospective observational study. Scand J Trauma Resusc Emerg Med. 2017; 25(1):18.
  2. Galvagno SM Jr, Haut ER, Zafar SN, et al. Association between helicopter vs ground emergency medical services and survival for adults with major trauma. JAMA. 2012; 307(15):1602-1610.
  3. Kunte SA, Anderson D, Brown-Espaillat K, Froehler MT. Total transfer time for ground vs. air transport for interhospital and scene transfers of acute stroke patients. J Stroke Cerebrovasc Dis. 2021; 30(6):105704.
  4. Nolan B, Haas B, Tien H, et al. Causes of delay during interfacility transports of injured patients transported by air ambulance. Prehosp Emerg Care. 2020; 24(5):625-633.
  5. Stewart K, Garwe T, Oluborode B, et al. Association of interfacility helicopter versus ground ambulance transport and in-hospital mortality among trauma patients. Prehosp Emerg Care. 2021; 25(5):620-628.

Government Agency, Medical Society, and Other Authoritative Publications:

  1. American College of Emergency Physicians. Policy Statements. Available at: Accessed on October 5, 2021.
  2. American College of Surgeons; Committee on Trauma; American College of Emergency Physicians; National Association of EMS Physicians; Pediatric Equipment Guidelines Committee; American Academy of Pediatrics. Equipment for ambulances. Bull Am Coll Surg. 2009; 94(7):23-29.
  3. Doucet J, Bulger E, Sanddal N, et al. Appropriate use of helicopter emergency medical services for transport of trauma patients: guidelines from the Emergency Medical System Subcommittee, Committee on Trauma, American College of Surgeons. J Trauma Acute Care Surg. 2013; 75(4):734-741.
  4. Lyng J, Adelgais K, Alter R, et al. Recommended essential equipment for basic life support and advanced life support ground ambulances 2020: A Joint Position Statement. Prehosp Emerg Care. 2021; 25(3):451-459.
  5. Medicare Benefit Policy Manual. Chapter 10 - Ambulance Services. April 13, 2018. Available at: Accessed on October 5, 2021.
  6. Palmetto GBA. Local Coverage Determination for Ambulance Services (L34549). Revised 07/29/2021. Available at: Accessed on October 5, 2021.
  7. Thomson DP, Thomas SH; 2002-2003 Air Medical Services Committee of the National Association of EMS Physicians. Guidelines for air medical dispatch. Prehosp Emerg Care. 2007 (2):265-271.

Emergency Transport







Medical Policy & Technology Assessment Committee (MPTAC) review. Updated Discussion/General Information and References sections.



MPTAC review. Updated Discussion/General Information and References sections. Reformatted coding section.



MPTAC review. Added note to Clinical Indications section regarding timeframe difference for ground and air transport. Updated Discussion/General Information and References sections.



MPTAC review. Updated References section.



MPTAC review. Clarifications to MN and NMN statements regarding mileage. Updated References section.



MPTAC review. Revisions made to NMN statements. Coding section updated. The document header wording updated from “Current Effective Date” to “Publish Date.”



MPTAC review. Updated formatting in Clinical Indications section.



MPTAC review. Updated Reference section. Removed ICD-9 codes from Coding section.



MPTAC review. Addition of “first responders deem to be life threatening” to Medically Necessary Statement. Updated Discussion/General Information and References.



MPTAC review. Updated References.



Updated Coding section with 01/01/2014 HCPCS changes.



MPTAC review. Updated References.



MPTAC review. No changes to Clinical Indications.



MPTAC review. Updated Rationale and Reference sections.



MPTAC initial document development. Moved position statement regarding air and water ambulance from CG-ANC-01 to CG-ANC-04.

Pre-Merger Organizations

Last Review Date

Document Number


Anthem Midwest



Air Ambulance Services

Anthem Virginia



Ambulance and Medical Transport

Anthem Maine



Ambulance Benefit Detail


Federal and State law, as well as contract language, and Medical Policy take precedence over Clinical UM Guidelines. We reserve the right to review and update Clinical UM Guidelines periodically. Clinical guidelines approved by the Medical Policy & Technology Assessment Committee are available for general adoption by plans or lines of business for consistent review of the medical necessity of services related to the clinical guideline when the plan performs utilization review for the subject. Due to variances in utilization patterns, each plan may choose whether to adopt a particular Clinical UM Guideline. To determine if review is required for this Clinical UM Guideline, please contact the customer service number on the member's card.

Alternatively, commercial or FEP plans or lines of business which determine there is not a need to adopt the guideline to review services generally across all providers delivering services to Plan’s or line of business’s members may instead use the clinical guideline for provider education and/or to review the medical necessity of services for any provider who has been notified that his/her/its claims will be reviewed for medical necessity due to billing practices or claims that are not consistent with other providers, in terms of frequency or in some other manner.

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