I have the AARP United Health Care Medicare supplement. This is taken directly from their website. I am glad you asked the question, as I was not aware that it only covered 60 days, or the $50k max. I signed up for this plan because it seemed to cover everything I needed, including some international travel. I do wish it lasted 90 days as that's what i am planning for my routine trips to Thailand.
Foreign Travel Emergency
Medicare does not cover any health care you receive outside of the United States. Medigap Plans C, D, F, G, M and N cover some emergency care outside the United States. After you meet the yearly $250 deductible, this benefit pays 80 percent of the cost of your emergency care during the first 60 days of your trip. There is a $50,000 lifetime maximum.