Our insurance was through Medicare United Health Care PLAN F. Plan F covers issues when you are out of the US. Our insurance picked up $44,000 and Dan covered the remaining costs. Your primary insurance is the first to be paid. If you travel out of the country frequently, you should check your policy coverage
You have just about used your lifetime Plan F coverage for emergency care outside of the USA.
Total bill ~55k, PlanF deductible ~11k, paid ~44k, you have ~7.5 gross remaining for lifetime out of USA use.
Of note for expats is the first 60 day limitation on Medigap plan coverage.
In the grand scheme of life, $50k isn't a significant amount of coverage. I doubt a foreign provider would accept a Medigap assignment.
Medicare Coverage Outside the United States
"Medigap plans C, D, E, F, G, H, I, J, M, and N pay 80% of the billed charges for certain medically necessary emergency care outside the U.S. after you meet a $250 deductible for the year. These Medigap policies cover foreign travel emergency care if it begins during the first 60 days of your trip, and if Medicare doesn’t otherwise cover the care. Foreign travel emergency coverage with Medigap policies has a lifetime limit of $50,000."