DAN insurance basically covers what your HMO doesn't. In many instances transportation can include medical flights which can be very costly. Your insurance may or may not cover this, but DAN will. A medicopter with trained personnel, flighing at very low altitudes, can run into thousands of dollars. The advantage of being in the states and using the services of a medical facility is your insurance is processed immediately. Out of the US, you should carry a credit card that has a lot of room. You will be expected to pay immediately, they will not bill your insurance. Bring your paperwork back and submit it for reimbursement. With DAN you know you are covered, and will be paid.
