In other words, the patient could not be transported by any other means of transportation without endangering their health. If the patient could be transported by means other than an ambulance, e.g., a wheelchair van, cars, a taxi, etc. without endangering the patient's health, then medical necessity does not exist. It does not make a difference whether or not the other means of transportation is actually available in the locality. The Medicare Carriers Manual lists situations in which medical necessity is presumed to be met. Despite the instructions to the carriers that these nine situations meet medical necessity, many carriers require additional justification.
Medical necessity is based on the patient's condition at the time of the trip.
Avoid the tendency to list the patient's past medical history, unless that is important in describing the condition at the time of transport. Use words to show why the ambulance was the only way this patient could be transported. Do not be confused and think that stating the purpose of the trip is the same as why the ambulance was needed. For example, a patient may be transported for an x-ray of the hip. This is the purpose of the trip.