Medicare is not available for health insurance outside the USA. Best to purchase a policy such as Seven Corners for health coverage outside the USA.
I just returned from Haiti and while I did not get sick and did not need a doctor or a hospital, I was very glad I had a policy from Seven Corners to cover me just in case I needed it.
If going to Haiti get shots for Typhoid fever, Hepatitis, and Tetanus. Also take medication for Malaria. Make sure to drink only bottled water. Don't put ice cubes in a beverage and make sure to brush teeth using bottled water. Don't wash hands with local water before eating. Wash hands with a germicide before eating. Eat food that is well cooked.
Following these guidelines I felt fine and did not get sick.
recommend this plan to a friend or relative.