In general, many health insurance plans, including Social Security Medicare, do not provide coverage when you travel outside the U.S. If an insurance plan covers "customary and reasonable" hospital costs abroad, it may not pay for your medical evacuation back to the U.S., which could be costly. You may also find that many foreign doctors and hospitals require payment in cash prior to providing care. Consider exploring your travel insurance options before your trip. You may also want to check with the country you plan to visit for detailed information about health insurance coverage and treatment in their area.