The CMS Medicare Claims Processing Manual states:

Ambulance transports

Emergency or urgent situations: In general, a notifier may not issue an ABN to a beneficiary who has a medical emergency or is under similar duress. Forcing delivery of an ABN during an emergency may be considered coercive. ABN usage in the ER may be appropriate in some cases where the beneficiary is medically stable with no emergent health issues.

Non-emergent / urgent ambulance transport: If the provider or supplier wants to transfer liability to the beneficiary, issuance of the ABN is mandatory for ambulance transport services if all of the following three criteria are met: 

1. The service being provided is a Medicare covered ambulance benefit under §1861(s)(7) of the SSA and regulations under this section as stipulated in 42 CFR §410.40 -.41
2. The health care provider or supplier believes that the service may be denied, in part or in full, as “not reasonable and necessary” under §1862(a)(1)(A) for the beneficiary on that occasion; and
3. The ambulance service is being provided in a non-emergency situation. (The patient is not under duress.) 

ABN issuance is mandatory only when a beneficiary’s covered ambulance transport is modified to a level that is not medically reasonable and necessary and will incur additional costs. If an ambulance transport is statutorily excluded from coverage because it fails to meet Medicare’s definition of the ambulance benefit, a voluntary ABN may be issued to notify the beneficiary of his/her financial liability as a courtesy.

 

Reference

• CMS IOM Pub. 100-04 Medicare Claims Processing Manual, Chapter 30, section 50.17