This thread raises and discusses a very complex set of issues. They all arise from the supposition someone gets seriously ill while abroad. Issues include where to get care, when to be evacuated home, how to be evacuated home, how to pay for the trip home, medical insurance coverage when you do get home, and where to get treated in the US.
The first choice for treatment is in the local area if expert local care is available. The problem is knowing if there are really skilled medical help available locally. To find that out may take some blunt questioning. (How many of these have you seen this week, month, year. What is your success ratio?) If you have Divers Alert Network coverage, the MD answering the DAN phone back in the states will be able to help you determine if local treatment is acceptable, or evacuation to home is advisable. This access to medical advise over the phone is a very valuable part of the service provided by DAN.
In many parts of the world medical/surgical care is every bit as good as that available in the US.
The second question is medical evacuation. If the patient can get onto a commercial carrier, pay for the first class ticket, the care that goes along with it, and get home. Of an air ambulance is necessary, realistically you must have evacuation insurance. I know of two sources: DAN, and AKC. DAN is least expensive, and provides good service. American Kennel Club charges $109 annually for member and family coverage.
They claim this coverage includes caring for your pet, and getting him back home if necessary. I have no experience with them, but just getting a pet shipped home is expensive. If I were traveling with a pet, I would sure investigate AKC coverage. They also claim expert medical advise.
This leaves the question of the medical insurance coverage if the patient has to be evacuated back to the states. A high deductable/low premium policy or "catastrophic coverage" is what most would arrange for. I would get as much coverage as possible. My own son was in an accident in 1985. The bill from the 1st hospital was slightly less than $250,000. (Insurance paid). He was then medically uninsurable, but we got him covered with a medical policy with a $25,000 deductable. Annual premium was about $250.00. Those numbers are from the mid 80's. Today they would be much scarier.
If evacuation is medically necessary, be prepared to intelligently choose where to go. If I am sick sick sick, and trying real hard to die right now, I would want to go to a major hospital known for it's expertise in what ever I am suffering from. More than that, if there are two hospitals side by side, one staffed by the professors, and the other the professors teaching hospital, I want to go to the teaching hospital.
I hope this clarifies some thinking.