Medicare itself does not cover health care in general when one is traveling outside the United States. There are some exceptions to that, but they are very specific and limited. For example if a policy holder lives in the United States and develops a problem that a foreign hospital which is closer than one in the U.S. could treat them for, then Medicare may pay for the treatment at that hospital. Those situations are outlined and can be reviewed at any of the numerous Medicare sites.
Medicare Supplemental Plans are called Medigap policies because they fill in where original Medicare coverage does not apply. They are fairly easy to compare because most states identify the different policies with letters. The Standard Medigap or Medicare Supplemental Plan letters are C, D, F, G, M and N. These policies provide emergency health care coverage outside the U.S. (Please note: Massachusetts, Minnesota and Wisconsin have Medicare Supplemental Plans that are similar to the standardized Medigap plans offered in other states, but are not the same.)
Medicare Supplemental Plans E, H, I, and J are no longer available. However, if one was purchased before June 1, 2010, it may still be used. These are part of the Medicare Supplemental Plans that provide foreign travel emergency health care outside the U.S.
Medicare Supplemental Plans C, D, E, F, G, H, I, J, M and N all pay 80% for certain medical emergencies outside the U.S. The policy holder must meet a yearly deductible of $250 and the emergency care must commence during the first 60 days of travel. There is also a $50,000 lifetime limit on foreign travel coverage.